struvite and Kidney-Calculi

Kidney stone disease is one of the oldest diseases known to medicine; however, the mechanisms of stone formation and development remain largely unclear. Over the past decades, a variety of theories and strategies have been developed and utilized in the surgical management of kidney stones, as a result of recent technological advances. Observations from the authors and other research groups suggest that there are five entirely different main mechanisms for kidney stone formation. Urinary supersaturation and crystallization are the driving force for intrarenal crystal precipitation. Randall's plaques are recognized as the origin of calcium oxalate stone formation. Sex hormones may be key players in the development of nephrolithiasis and may thus be potential targets for new drugs to suppress kidney stone formation. The microbiome, including urease‑producing bacteria, nanobacteria and intestinal microbiota, is likely to have a profound effect on urological health, both positive and negative, owing to its metabolic output and other contributions. Lastly, the immune response, and particularly macrophage differentiation, play crucial roles in renal calcium oxalate crystal formation. In the present study, the current knowledge for each of these five aspects of kidney stone formation is reviewed. This knowledge may be used to explore novel research opportunities and improve the understanding of the initiation and development of kidney stones for urologists, nephrologists and primary care.

Topics: Apatites; Calcinosis; Calcium Oxalate; Calcium Phosphates; Gastrointestinal Microbiome; Humans; Kidney; Kidney Calculi; Struvite; Uric Acid; Urolithiasis

Compared to adults, urolithiasis is less common in children, with a definite rise in incidence, especially among young adults (Tasian et al. in Clin J Am Soc Nephrol 11:488, 2016). In the last 25 years, the incidence in children has increased by approximately 6-10% annually, for reasons still unknown, with an associated significant increase in related health care-related expenditures (Hyams and Matlaga in Transl Androl Urol 3(3):278-83, 2014). It has been shown that there is twice as high a risk of chronic kidney disease (CKD) or end stage renal disease (ESRD) in stone formers compared to non-stone formers (Tasian et al. 2016). While calcium-containing stones are by far the most common category of stone encountered in both children and adults, non-calcium stones are more common in children than adults and have been shown in several studies to be associated with greater morbidity and lower renal function than calcium stones (Issler et al. in BMC Nephrol 18(1):136, 2017; Gambaro et al. in J Urol 198:268-273, 2017). This could be related to the challenges in the management of non-calcium-containing stones due to associated infection or metabolic derangements, further leading to recurrence and loss of renal function. There is currently a gap in our understanding of how to appropriately and effectively encounter and manage patients with non-calcium-containing stones, as such cases are encountered less frequently. Identification of stone composition and appropriate management is very important to reduce serious complications and recurrence, especially in non-calcium stones. We present a review of diagnosis and management of non-calcium-containing stones in the pediatric population, in hopes of providing more clarity to providers and promoting a consideration of non-calcium stone composition with all children presenting with urolithiasis.

Topics: Calcium Oxalate; Calculi; Disease Management; Female; Humans; Kidney Calculi; Lithotripsy; Male; Pediatrics; Prognosis; Severity of Illness Index; Struvite; Treatment Outcome; Uric Acid; Urolithiasis

Infection stones-which account for 10-15% of all urinary calculi-are thought to form in the presence of urease-producing bacteria. These calculi can cause significant morbidity and mortality if left untreated or treated inadequately; optimal treatment involves complete stone eradication in conjunction with antibiotic therapy. The three key principles of treating struvite stones are: removal of all stone fragments, the use of antibiotics to treat the infection, and prevention of recurrence. Several methods to remove stone fragments have been described in the literature, including the use of urease inhibitors, acidification therapy, dissolution therapy, extracorporeal shockwave lithotripsy, ureteroscopy, percutaneous nephrolithotomy (PCNL), and anatrophic nephrolithotomy. PCNL is considered to be the gold-standard approach to treating struvite calculi, but adjuncts might be used when deemed necessary. When selecting antibiotics to treat infection, it is necessary to acquire a stone culture or, at the very least, urine culture from the renal pelvis at time of surgery, as midstream urine cultures do not always reflect the causative organism.

Topics: Algorithms; Anti-Bacterial Agents; Crystallization; Drug Therapy, Combination; Hemostatics; Humans; Kidney Calculi; Lithotripsy; Magnesium Compounds; Nephrostomy, Percutaneous; Phosphates; Struvite; Treatment Outcome; Urease; Ureteroscopy; Urinary Tract Infections

Plasma levels and urinary amino acid excretions were estimated by high-performance liquid chromatography in 15 control subjects and 36 stone formers (SFs) classified according to the stone type: (1) 22 cases with calcium oxalate stones; (2) four cases with pure uric acid stones; (3) 10 cases with magnesium-ammonium phosphate stones, either pure or mixed with apatite. Some types of stones (namely oxalate and uric acid calculi) are mainly formed as a result of a metabolic deficiency that may affect the amino acid metabolism, and thus may be reflected in the urinary amino acid pattern. Data demonstrated clearly that there is a general tendency towards decreased amino acid excretions in all SFs with all types of stones. As a whole, one can observe a higher percentage of patients with calcium oxalate and phosphate calculosis, who have low urine excretions of amino acids; about 50% are the SFs with lower urine excretion of serine, glycine, taurine and i-leucine; the high percentage of patients with CaOX calculi shows lower urine excretions of tyrosine and ornithine.

Topics: Adult; Amino Acids; Apatites; Calcium Oxalate; Chromatography, High Pressure Liquid; Female; Humans; Kidney Calculi; Magnesium Compounds; Male; Middle Aged; Phosphates; Struvite; Uric Acid

Renal stone disease covers kidney and lower urinary tract stones caused by a variety of conditions, including metabolic and inherited disorders, and anatomical defects with or without chronic urinary infection. Most cases are idiopathic, in which there is undoubtedly a genetic predisposition, but where environmental and lifestyle factors play an important role. Indeed, it is becoming apparent that renal stone disease is often part of a larger 'metabolic picture' commonly associated with type 2 diabetes, obesity, dyslipidaemia, and hypertension. Renal stone disease is a growing problem in the UK (and other developed and developing populations) with a cross-sectional prevalence of ∼1.2%. This means that there are currently ∼720,000 individuals with a history of kidney stones in the UK. Almost 40% of first-time stone formers will form a second stone within 3 years of the first episode if no prophylactic measures are instituted to prevent stone recurrence, since removal or disintegration of the first stone does not treat the underlying cause of stones in the majority of patients. The age of onset is getting younger and the sex ratio (until recently more men than women) is becoming almost even. Metabolic screening remains an important part of investigating renal stone disease, but to the disappointment and frustration of many doctors, medical treatment is still essentially pragmatic, except perhaps in cystinuria, and to a limited extent in primary hyperoxaluria (if pyridoxine-sensitive); although newer treatments may be emerging. This review summarizes current thinking and provides a practical basis for the management of renal stone disease.

Topics: Age of Onset; Calcium Oxalate; Calcium Phosphates; Cross-Sectional Studies; Cystine; Diabetes Mellitus, Type 2; Female; Fluid Therapy; Genetic Predisposition to Disease; Humans; Kidney Calculi; Lithotripsy; Magnesium Compounds; Male; Metabolic Syndrome; Patient Care Management; Phosphates; Prevalence; Recurrence; Risk Factors; Struvite; Uric Acid

The American Urological Association Nephrolithiasis Guidelines Panel recently conducted a critical meta-analysis of the existing literature to determine the optimal management for staghorn calculi. This article briefly discusses the pathophysiology of staghorn calculi and, based on the panel's recommendations, examines the alternative medical treatments (eg, chemolysis) and surgical treatments (eg, shock wave lithotripsy, open surgery, ureteroscopy, and percutaneous nephrolithotomy) available for staghorn patients. Considering the various modalities for staghorn disease, percutaneous nephrolithotomy should be the first-line treatment for most patients based on its superior efficacy and low morbidity.

Topics: Humans; Kidney Calculi; Lithotripsy; Magnesium Compounds; Nephrostomy, Percutaneous; Phosphates; Struvite; Ureteroscopy

Kidney stones are a common disorder of the urinary tract. Nephrolithiasis is a morbid and expensive disease. The prevalence and incidence are estimated at 5-10% and 100-300/100,000/year, respectively. Relapses occur in 50-70% of all cases. For these reasons, prevention of stone formation is of great importance. Knowing the composition of the calculus is thus fundamental for a more complete evaluation of the metabolic study. The nature of the calculus in fact helps the physician to find a convenient metaphylaxis consisting of both sanitary and therapeutic measures. Study of the composition of urinary stones remains one of the most interesting aspects of the lithiasic pathology today. Presently crystallographic examination constitutes one of the most precise and less expensive methodologies to identify the nature of the concretion. This method also allows the urologist to catalogue the typology of the lithiasis during endoscopy.

Topics: Calcium Oxalate; Calcium Phosphates; Crystallography; Humans; Kidney Calculi; Magnesium Compounds; Nephrolithiasis; Phosphates; Struvite; Uric Acid

Renal lithiasis is a multifactorial disease. An important number of etiologic factors can be adequately modified through diet, since it must be considered that the urine composition is directly related to diet. In fact, the change of inappropriate habitual diet patterns should be the main measure to prevent kidney stones. In this paper, the relation between different dietary factors (liquid intake, pH, calcium, phosphate, oxalate, citrate, phytate, urate and vitamins) and each type of renal stone (calcium oxalate monohydrate papillary, calcium oxalate monohydrate unattached, calcium oxalate dihydrate, calcium oxalate dihydrate/hydroxyapatite, hydroxyapatite, struvite infectious, brushite, uric acid, calcium oxalate/uric acid and cystine) is discussed.

Topics: Calcium Oxalate; Calcium Phosphates; Cystine; Diet; Diet, Vegetarian; Dietary Proteins; Drinking; Durapatite; Humans; Hydrogen-Ion Concentration; Kidney Calculi; Magnesium Compounds; Nutritional Physiological Phenomena; Phosphates; Sodium Chloride, Dietary; Struvite; Uric Acid

A metabolic etiology is the most common cause for pediatric kidney stones. Appropriate evaluation of affected children should include assessment of stone type, if available, and assessment of predisposing factors in all cases. This review discusses the metabolic disorders that lead to nephrolithiasis with respect to the development of calcium, uric acid, struvite, and cystine stones. Environmental and hereditary factors are summarized to provide a guide in the evaluation of pediatric stone formers.

Topics: Calcium; Child; Cystine; Humans; Kidney Calculi; Magnesium Compounds; Phosphates; Struvite; Uric Acid

About 5% of American women and 12% of men will develop a kidney stone at some time in their life, and prevalence has been rising in both sexes. Approximately 80% of stones are composed of calcium oxalate (CaOx) and calcium phosphate (CaP); 10% of struvite (magnesium ammonium phosphate produced during infection with bacteria that possess the enzyme urease), 9% of uric acid (UA); and the remaining 1% are composed of cystine or ammonium acid urate or are diagnosed as drug-related stones. Stones ultimately arise because of an unwanted phase change of these substances from liquid to solid state. Here we focus on the mechanisms of pathogenesis involved in CaOx, CaP, UA, and cystine stone formation, including recent developments in our understanding of related changes in human kidney tissue and of underlying genetic causes, in addition to current therapeutics.

Topics: Animals; Calcium Oxalate; Calcium Phosphates; Drug-Related Side Effects and Adverse Reactions; Female; Humans; Kidney Calculi; Magnesium Compounds; Male; Pharmaceutical Preparations; Phosphates; Struvite

Topics: Calcium; Citric Acid; Colic; Glycoproteins; Humans; Hyperoxaluria; Kidney Calculi; Magnesium Compounds; Phosphates; Recurrence; Risk Factors; Struvite; Uric Acid

Topics: Calcium; Child; Child, Preschool; Cystine; Female; Hematuria; Humans; Kidney Calculi; Magnesium Compounds; Male; Metabolic Diseases; Oxalates; Phosphates; Struvite; Uric Acid; Urinalysis; Urinary Calculi; Urinary Tract Infections

Topics: Acidosis, Renal Tubular; Calcium; Calcium Oxalate; Citric Acid; Cysteine; Humans; Kidney Calculi; Magnesium Compounds; Phosphates; Struvite; Uric Acid

Currently, only struvite stones are regarded as deriving from bacteria. Recent work has suggested that calcium-based stones might also have an infectious origin. Nanobacteria, small intracellular bacteria found in human kidney stones, are capable of forming a calcium phosphate shell, and thus could serve as crystallization centres for renal calculi formation. Until now, however, all trials performed to confirm the presence of nanobacteria in human calculi, serum or urine have failed. In a hyperoxaluric rat model, tissue-residing macrophages were able to remove interstitial crystals and thus may not be primarily engaged in defending against micro-organisms, if present.

Topics: Animals; Bacterial Infections; Crystallization; Hemostatics; Humans; Kidney Calculi; Magnesium Compounds; Phosphates; Rats; Struvite

Struvite stones constitute only about 2-3% of the stones reaching the laboratory for analysis, but the clinical problems they create including sepsis and even renal demise are greater than with any other stone type. This article reviews the evidence that bacterial urease, usually from a Proteus species, is responsible for the chemical changes in urine which result in struvite formation. Available urease inhibitors and other forms of medical management of patients with these stones are discussed. A patient with struvite stones should be assumed to have a progressive disease which cannot be ignored. Even after seemingly successful elimination of stones with lithotripsy and/or percutaneous nephrolithotomy, careful medical follow-up is critical. The medical profession is probably underutilizing postprocedure hemiacidrin irrigation because of shortsighted financial considerations. Primary-care physicians need to be educated in the importance of aggressive management of Proteus and other urea-splitting infections.

Topics: Adult; Child; Enzyme Inhibitors; Humans; Kidney Calculi; Magnesium Compounds; Phosphates; Struvite; Urease

Effective management of struvite calculi requires a comprehensive approach to eliminate the stone burden and prevent stone recurrence. These stones occur more frequently in women, infants, and the elderly, as these patients are at greater risk for urinary tract infections. All patients should have routine laboratory testing as well as an excretory urogram. Appropriate urine cultures should be completed. Definitive management should promptly follow diagnosis. Percutaneous nephrolithotomy with or without SWL is the usual treatment. Appropriate antibiotic use is helpful; magnesium and phosphorus restriction and administration of urease inhibitors are less valuable.

Topics: Anti-Bacterial Agents; Endoscopy; Enzyme Inhibitors; Humans; Kidney Calculi; Lithotripsy; Magnesium Compounds; Phosphates; Struvite; Urease; Ureteroscopy; Urology

Topics: Calcium; Citric Acid; Cystinuria; Humans; Kidney Calculi; Magnesium Compounds; Oxalates; Phosphates; Struvite; Uric Acid

Urinary calculi have plagued man over the centuries. The epidemiology and pathogenesis of infection have been studied. The curative treatment remains problematic. Without therapy, a vicious cycle of stone formation occurs. This results in renal damage and even death. Multimodality therapy is the key. Nonoperative treatment leads to progressive renal damage. The combination of maximal surgical ablation and medical therapy is synergistic. The combination of PCNL-ESWL has not appeared to produce ill effects. PCNL-ESWL is a less morbid surgical alternative than open surgical procedures. Adjunctive medical therapy, such as culture-specific antibiotics and urease inhibitors, complements surgical ablation by reducing the morbidity with persistent UTIs and stone recurrence. The urologist today must approach struvite staghorns with a vast armamentarium of surgical and medical techniques. Each patient requires a unique solution.

Topics: Humans; Kidney Calculi; Lithotripsy; Magnesium Compounds; Nephrostomy, Percutaneous; Phosphates; Struvite; Urease; Urine

Topics: Algorithms; Combined Modality Therapy; Cystine; Humans; Kidney Calculi; Kidney Pelvis; Lithotripsy; Magnesium Compounds; Nephrostomy, Percutaneous; Phosphates; Struvite; Treatment Outcome

The treatment of small renal pelvic and ureteric calculi can be performed with relative safety and efficacy using lithotripsy or an endourological method. There remains however, a proportion of stones that are resistant to these methods because of their anatomical position, physical composition or sheer size. To these stones must be applied a treatment strategy using the variety of techniques to their maximum advantage. This article aims to review the accumulated experience on the management of these more complex urinary calculi.

Topics: Calcium Phosphates; Combined Modality Therapy; Cystine; Humans; Kidney; Kidney Calculi; Lithotripsy; Magnesium; Magnesium Compounds; Nephrostomy, Percutaneous; Phosphates; Struvite

Selective medical therapy of nephrolithiasis is highly effective in preventing new stone formation. A remission rate of greater than 80% and an overall reduction in individual stone formation rate of greater than 90% can be obtained in patients with nephrolithiasis. In patients with mild to moderate severity of stone disease, virtually total control of stone disease can be achieved with a remission rate of greater than 95%. The need for stone removal may be dramatically reduced by an effective prophylactic program (Fig 6). Selective pharmacological therapy of nephrolithiasis also encompasses the advantages of overcoming nonrenal complications as well as averting certain side effects that may be caused by nonselective medical therapy. Despite these advantages, it is clear that selective medical therapy cannot provide total control of stone disease. A satisfactory response requires continued, dedicated compliance by patients to the recommended program and a commitment by the physician to provide long-term follow-up and care.

Topics: Calcium; Citrates; Citric Acid; Combined Modality Therapy; Diagnosis, Differential; Diuretics; Gout; Humans; Kidney Calculi; Magnesium; Magnesium Compounds; Oxalates; Oxalic Acid; Parathyroidectomy; Phosphates; Struvite; Uric Acid

Urinary stone disease is a common affliction in our society and may affect 1 to 5 per cent of the population. The physician involved in caring for the stone-forming patient must have a thorough understanding of the metabolic as well as anatomic abnormalities that may lead to repeat stone formation. The authors review the common metabolic abnormalities frequently seen in the stone-forming patient and present the current medical management of these problems. Ongoing changes in the surgical approach to urinary stones are also discussed.

Topics: Calcium; Crystallization; Cystine; Cystinuria; Humans; Kidney Calculi; Magnesium; Magnesium Compounds; Phosphates; Physical Examination; Struvite; Tomography, X-Ray Computed; Ultrasonography; Uric Acid; Urinary Calculi; Urinary Tract Infections; Urine; Urography

Advances in renal lithiasis research have contributed to a better understanding of the many varied factors that contribute to renal calculus formation. Utilizing the newer techniques of ambulatory metabolic evaluation, we can establish a specific diagnosis in 95% of recurrent stone-formers. Since a significant percentage of initial stone-formers will never have a second episode, it is essential to establish the natural history of the patient's stone disease prior to initiating potentially life-long medical therapy. The majority of initial stone-formers can be managed with education concerning modest dietary restrictions and increased fluid intake. For the recurrent stone-former with metabolically active stone disease, it is probably best to design medical therapy to treat the specific urinary chemical abnormality or disease process.

Topics: Acidosis, Renal Tubular; Bacterial Infections; Calcium; Crystallography; Cystinuria; Diuresis; Fluid Therapy; Humans; Intestinal Absorption; Kidney; Kidney Calculi; Magnesium; Magnesium Compounds; Oxalates; Patient Education as Topic; Phosphates; Recurrence; Risk; Struvite; Uric Acid; Urography

Topics: Acidosis, Renal Tubular; Calcium; Cystinuria; Humans; Hydrogen-Ion Concentration; Hyperparathyroidism; Kidney Calculi; Magnesium; Magnesium Compounds; Phosphates; Proteus Infections; Struvite; Urine

The use of percutaneous nephrostomy catheters has allowed access to intrarenal urinary calculi for dissolution. Renacidin is the successful agent for dissolving struvite stones. THAM-E is the most effective agent for the intrarenal dissolution of cystine stone. Calcium oxalate stones are still resistant to dissolution techniques.

Topics: Citrates; Cystine; Humans; Kidney; Kidney Calculi; Magnesium; Magnesium Compounds; Methods; Phosphates; Skin; Solubility; Struvite; Therapeutic Irrigation; Uric Acid

Topics: Acidosis, Renal Tubular; Allopurinol; Benzothiadiazines; Calcium; Calcium, Dietary; Cystinuria; Diuretics; Humans; Hyperparathyroidism; Kidney Calculi; Magnesium; Magnesium Compounds; Oxalates; Penicillamine; Phosphates; Quaternary Ammonium Compounds; Sodium Chloride Symporter Inhibitors; Struvite; Uric Acid

The treatment of patients with staghorn calculi remains a challenging problem. Combination therapy using percutaneous nephrolithotomy and extracorporeal shock wave lithotripsy has been recommended as the best option for most patients. Using this technique, 10 (83%) of 12 renal units with partial or complete staghorn calculi were rendered stone-free, with no significant septic episodes or serious complications. Blood transfusion was necessary in three patients. "Sandwich" therapy using initial percutaneous debulking followed by extracorporeal shock wave lithotripsy and/or "second-look" nephroscopy offers patients a high likelihood of achieving a stone-free state while avoiding the morbidity and lengthy recovery associated with open surgery.

Topics: Combined Modality Therapy; Follow-Up Studies; Humans; Kidney Calculi; Lithotripsy; Magnesium Compounds; Nephrostomy, Percutaneous; Phosphates; Radiography; Struvite; Treatment Outcome

The prevalence of arterial hypertension (HT) was investigated in 258 patients (171 m, 87 f, 22-68 years) with a history of primary stone disease. HT was detected in 64 patients (24.8%), with no difference between males (25.7%) and females (23.0%). The prevalence of HT by age was very similar to that of a general population, especially in the calcium stone group. The discriminant analysis demonstrated that the composition of stones, other than the age and body weight of the patients, were the main factors associated with HT. As far as the different kind of stone is concerned, the prevalence of HT was higher in patients with uric acid (17/37, 45.9%) and struvite stones (11/27, 40.7%) than in calcium stone formers (35/188, 18.6%) (chi 2 16.31, p < 0.001). The prevalence of hypercalciuria was higher in the calcium stone group than in uric acid or struvite stone patients (36.4 vs. 9.7 vs. 13.7%; chi 2 10.35, p < 0.01). Furthermore, the hypercalciuria showed a trend to be more prevalent in the untreated (47.0%) than in the treated (31.2%) hypertensives, or normotensives (35.1%). Uric acid stone formers were older, heavier and with higher triglycerides and uric acid plasma levels than calcium or struvite patients. Also the struvite stone formers were older than the calcium stone ones. Our data suggest that the prevalence of HT in kidney stone patients and particularly in calcium stone formers is similar to that of a general population. The role of hypercalciuria as the link for HT-urolithiasis association seems quite uncertain. Struvite and uric acid stone formers have higher risk for HT than calcium stone formers, probably due to the old age or to the associated metabolic abnormalities.

Topics: Adult; Aged; Calcium; Female; Humans; Hypertension, Renal; Kidney Calculi; Magnesium Compounds; Male; Middle Aged; Phosphates; Struvite; Uric Acid

We studied the effects of the bacterial urease inhibitor acetohydroxamic acid on the growth of struvite stones in the urinary tract. Eighteen patients who received acetohydroxamic acid (15 mg per kilogram of body weight per day, in divided oral doses) for a mean of 15.8 months were compared in a randomized double-blind study with 19 patients who received placebo for a mean of 19.6 months. Seven patients given placebo reached a pre-determined end point: a 100 per cent increase in the two-dimensional surface area of their stones. No patient who received acetohydroxamic acid had a doubling of stone size (P less than 0.01). Nine patients receiving the drug and one patient receiving placebo required a decrease in dosage or cessation of treatment because of adverse effects (P less than 0.01). Episodes of tremulousness (n = 5, P less than 0.05), which reversed with a decrease in drug dose, and phlebothrombosis (n = 3, P not significant) were limited to the group given acetohydroxamic acid. We conclude that acetohydroxamic acid effectively inhibits the growth of struvite stones in the short term in patients infected with urea-splitting bacteria, but the prevalence of adverse reactions appears to be high and the toxicity and effectiveness of long-term therapy for struvite nephrolithiasis remain to be defined.

Topics: Adult; Double-Blind Method; Drug Evaluation; Female; Humans; Hydroxamic Acids; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Radiography; Random Allocation; Struvite; Urine

Kidney stones are a highly prevalent disease worldwide. Additionally, both environmental and occupational exposure to Pb and Cd continue to be prevalent globally and can result in renal toxicity. The objective of this study was to examine the potential presence of Pb and Cd in kidney stones, and to assess for correlation with demographic factors including smoking, gender, age, and kidney stone matrix composition.. Patient kidney stones (n = 96) were analyzed using Fourier transform infrared spectroscopy to identify the stone constituents. Cd and Pb concentrations (µg/g) were determined by inductively coupled plasma mass spectrometry. Cd and Pb concentrations were correlated using bivariable and multivariable statistical analysis with demographic factors (age, gender, smoking status), and kidney stone composition.. Kidney stone Cd (median 0.092 µg/g, range 0.014 to 2.46) and Pb concentrations (median 0.95 µg/g, range 0.060 to 15.4) were moderately correlated (r = 0.56, P < 0.0001). Cd concentrations were positively associated with patient history of smoking, patient age, and calcium oxalate monohydrate levels while negatively associated with struvite and uric acid/uric acid dihydrate. Pb concentrations were positively associated with females and apatite levels while negatively associated with uric acid/uric acid dihydrate. After holding constant other stone type composition levels, smoking status, and age, both Pb and Cd were positively associated with apatite and negatively associated with uric acid/uric acid dihydrate, struvite, and calcium carbonate.. Cd and Pb kidney stone concentrations are associated with specific kidney stone types. Cd and Pb kidney stone concentrations are both associated with smoking.

Topics: Apatites; Cadmium; Demography; Female; Humans; Kidney Calculi; Lead; Smoking; Struvite; Uric Acid

As part of the management of nephrolithiasis, determination of chemical composition of stones is important. Our objective in this study is to assess urologists' accuracy in making visual, intraoperative determinations of stone composition.. We conducted a REDCap survey asking urologists to predict stone composition based on intraoperative images of 10 different pure-composition kidney stones of 7 different types: calcium oxalate monohydrate (COM), calcium oxalate dihydrate (COD), calcium phosphate (CP) apatite, CP brushite, uric acid (UA), struvite (ST) and cystine (CY). To evaluate experience, we examined specific endourologic training, years of experience, and number of ureteroscopy (URS) cases/week. A self-assessment of ability to identify stone composition was also required.. With a response rate of 26% (366 completed surveys out of 1,370 deliveries), the overall accuracy of our cohort was 44%. COM, ST, and COD obtained the most successful identification rates (65.9%, 55.7%, and 52.0%, respectively). The most frequent misidentified stones were CP apatite (10.7%) and CY (14.2%). Predictors of increased overall accuracy included self-perceived ability to determine composition and number of ureteroscopies per week, while years of experience did not show a positive correlation.. Although endoscopic stone recognition can be an important tool for surgeons, it is not reliable enough to be utilized as a single method for stone identification, suggesting that urologists need to refine their ability to successfully recognize specific stone compositions intraoperatively.

Topics: Apatites; Calcium Oxalate; Cystine; Humans; Kidney Calculi; Struvite; Urinary Calculi; Urologists

To define risk factors and perioperative outcomes for matrix stones and compare these outcomes with struvite and calcium stone cohorts.. A retrospective cohort study comparing matrix stones (n=32), struvite stones (n=23) and a matched, calcium stone control group (n=32) was performed. Two-way ANOVA was used to compare the groups for continuous variables. Chi-square tests were used to compare categorical variables. Significance was set at P <.05. All statistical tests were performed using R (v1.73).. We identified no differences in age, gender, or BMI between the three groups. Matrix and struvite stones were more likely to have a history of prior stone surgery and recurrent UTIs compared to calcium stones (P=.027 and P <.001, respectively). Struvite stones were more likely to present as staghorn calculi compared to matrix or calcium stones (56.5% vs 21.7% vs 18.8%, P=.006). There were no significant differences in postoperative stone free rates (P=.378). No significant differences in postoperative infectious complications were identified. Matrix stones were more likely to have Candida on stone culture compared to the struvite or calcium stones (P <.0001).. Matrix and struvite stones were more likely have a history of stone surgery and preoperative recurrent UTIs. Struvite stones were more likely to present as staghorn calculi. Matrix stones were more likely to have Candida present in stone cultures. However, no difference in postoperative infectious outcomes or stone free rates were identified. Further study with larger cohorts is necessary to distinguish matrix stone postoperative outcomes from struvite and calcium stones.

Topics: Calcium; Female; Humans; Kidney Calculi; Male; Phosphates; Postoperative Complications; Retrospective Studies; Staghorn Calculi; Struvite; Uric Acid

Topics: Female; Humans; Hypercalciuria; Kidney Calculi; Male; Nephrolithotomy, Percutaneous; Retrospective Studies; Struvite; Ureteroscopy

The aim of the study was to prospectively evaluate safety and efficacy of bilateral same session ureterorenoscopy (BSS-FURS) for management of bilateral renal calculi.. A prospective comparative study was designed to compare the results of BSS-FURS with unilateral flexible ureterorenoscopy (U-FURS) for management of renal calculi between June 2003 and May 2016. A sample size of 55 patients in each arm was calculated considering a 20% increase in the incidence of complications with BSS-FURS over 15% complication rate in U-FURS (alpha = 0.05; Beta = 0.90). Patient demographics, stone burden, total operative time, postoperative creatinine level, duration of hospital stay, perioperative complications and stone free rate (SFR) were compared in both the groups. The literature pertaining to BSS-FURS was reviewed.. Although the study group patients had higher overall stone burden (18.60 ± 7.70 mm vs. 13.32 ± 6.43 mm) and significantly longer operative time (48.30 ± 16.71 min vs. 32.95 ± 13.05 min;. BSS-FURS is a safe and efficient procedure for the management of bilateral renal calculi in the hands of an experienced endourologist. It has comparable SFR and morbidity compared to U-FURS. Caution should be exercised in patients with struvite stones, as they are more likely to develop postoperative fever.

Topics: Humans; Kidney Calculi; Lithotripsy, Laser; Prospective Studies; Retrospective Studies; Struvite; Treatment Outcome; Ureteroscopy

Topics: Calcium; Calcium Oxalate; Cystine; Humans; Kidney Calculi; Struvite; Uric Acid; Urinary Calculi

This Swiss LithoClast. Kidney stone phantoms were made with Begostone in a powder to water ratio (15:3-15:6). Complete stone clearance (seconds) was calculated and impact and frequency were adjusted and repeated N = 3. Intra renal pressure (IRP) was then measured in a porcine kidney model.. Stone phantoms with physical properties similar to struvite were cleared best with 100% impact and frequency of 12 Hz. Both uric acid stone phantoms and calcium phosphate stone phantoms were cleared most efficiently with an impact of 30% and a frequency of 4 Hz. The mean time to clear uric acid stone phantoms was 83 s versus 217 s for calcium phosphate stone phantoms. Similarly, for calcium oxalate stone phantoms, an impact of 30% and a frequency of 4 Hz was associated with the fastest clearance time, mean 204 s. However, the differences between 4, 8 and 12 Hz were not statistically significant. At a suction level of 60% or higher, IRP became negative.. These results indicate that stone phantoms of hard kidney stones are cleared more efficiently at lower impact and frequency settings. With regard to suction, a setting of ≤ 50% appears to be the optimal setting.

Topics: Animals; Calcium Oxalate; Kidney Calculi; Nephrostomy, Percutaneous; Powders; Struvite; Swine; Uric Acid; Water

In lithogenesis, for a stone to form it is necessary that the urine is supersaturated with respect to the salt that will constitute the future stone. The objective was to analyze the urinary saturations of Calcium Oxalate (CaOxa), brushite (calcium phosphate), struvite (ammonium-magnesium phosphate) and uric acid (UA) in children with and without lithiasis. Correlate them with the different parameters involved in the lithiasic process. And compare saturations in children with or without overweight.. We examined 108 healthy children and 53 patients diagnosed with lithiasis. In 24-h urine, the different biochemical parameters involved in lithiasis and the saturation levels of CaOxa, brushite, struvite and UA.. We studied 108 healthy children with a mean age of 9.5 ± 3.9 years. Renal lithiasis was diagnosed in 53 patients with an average age of 10.5 ± 5.8 years. Children with lithiasis had higher saturation values of CaOxa (4.86 ± 2.71 vs. 3.15 ± 1.99,. The mean values of calcium oxalate and brushite saturations were higher in children with lithiasis. Uric acid saturation was elevated in overweight children. Finally, urinary pH greatly influenced uric acid saturation.

Topics: Adolescent; Ammonium Compounds; Calcium Oxalate; Calcium Phosphates; Child; Child, Preschool; Humans; Kidney Calculi; Overweight; Struvite; Uric Acid; Urinary Calculi

Hounsfield units (HU) are a measure of radiodensity, related to the density of a tissue and the composition of kidney stones. Hounsfield density is what is related to the composition of kidney stones. In the standard acquisition method, these measures are arbitrary and dependent on the operator. This study describes the implementation of a technique based on the HU and Hounsfield density to predict the stone compositions of patients with nephrolithiasis. By conventional percutaneous nephrolithotomy, thirty kidney stone samples corresponding to the cortex, middle, and nucleus were obtained. The HU were obtained by CT scanning with a systematic grid. Hounsfield density was calculated as the HU value divided by the stone's greatest diameter (HU/mm). With that method and after analyzing the samples by IR-spectroscopy, anhydrous uric acid and ammonium magnesium phosphate were identified as the compounds of kidney stones. Additionally, anhydrous uric acid, magnesium ammonium phosphate, and calcium oxalate monohydrate were identified via Hounsfield density calculation. The study identified HU ranges for stone compounds using a systematic technique that avoids bias in its analysis. In addition, this work could contribute to the timely diagnosis and development of personalized therapies for patients with this pathology.

Topics: Calcium Oxalate; Humans; Kidney Calculi; Nephrolithotomy, Percutaneous; Retrospective Studies; Struvite

To study urinary stone composition patterns in different populations around the world.. Data were collected by reviewing charts of 1204 adult patients of 10 countries with renal or ureteral stones (> 18 years) in whom a stone analysis was done and available. Any method of stone analysis was accepted, but the methodology had to be registered.. In total, we observed 710 (59%) patients with calcium oxalate, 31 (1%) with calcium phosphate, 161 (13%) with mixed calcium oxalate/calcium phosphate, 15 (1%) with carbapatite, 110 (9%) with uric acid, 7 (< 1%) with urate (ammonium or sodium), 100 (9%) with mixed with uric acid/ calcium oxalate, 56 (5%) with struvite and 14 (1%) with cystine stones. Calciumcontaining stones were the most common in all countries ranging from 43 to 91%. Oxalate stones were more common than phosphate or mixed phosphate/oxalate stones in most countries except Egypt and India. The rate of uric acid containing stones ranged from 4 to 34%, being higher in Egypt, India, Pakistan, Iraq, Poland and Bulgaria. Struvite stones occurred in less than 5% in all countries except India (23%) and Pakistan (16%). Cystine stones occurred in 1% of cases.. The frequency of different types of urinary stones varies from country to country. Calcium-containing stones are prevalent in all countries. The frequency of uric acid containing stones seems to depend mainly on climatic factors, being higher in countries with desert or tropical climates. Dietary patterns can also lead to an increase in the frequency of uric acid containing stones in association with high obesity rates. Struvite stones are decreasing in most countries due to improved health conditions.

Topics: Adult; Calcium Oxalate; Humans; Kidney Calculi; Struvite; Ureteral Calculi; Urinary Calculi

Human kidney stones form. Stone fragments were collected from a randomly chosen cohort of 20 patients using standard percutaneous nephrolithotomy (PCNL). Fourier transform infrared (FTIR) spectroscopy indicated that 18 of these patients were calcium oxalate (CaOx) stone formers, whereas one patient formed each formed brushite and struvite stones. This apportionment is consistent with global stone mineralogy distributions. Stone fragments from seven of these 20 patients (five CaOx, one brushite, and one struvite) were thin sectioned and analyzed using brightfield (BF), polarization (POL), confocal, super-resolution autofluorescence (SRAF), and Raman techniques. DNA from remaining fragments, grouped according to each of the 20 patients, were analyzed with amplicon sequencing of 16S rRNA gene sequences (V1-V3, V3-V5) and internal transcribed spacer (ITS1, ITS2) regions.. Bulk-entombed DNA was sequenced from stone fragments in 11 of the 18 patients who formed CaOx stones, and the patients who formed brushite and struvite stones. These analyses confirmed the presence of an entombed low-diversity community of bacteria and fungi, including

Topics: Bacteria; Calcium Oxalate; Calcium Phosphates; Fungi; Humans; Kidney Calculi; RNA, Ribosomal, 16S; Struvite

This study aims to identify clinical factors that may predispose struvite stone patients to urosepsis following percutaneous nephrolithotomy (PCNL).. A retrospective review was conducted on patients who received PCNL for struvite stones. The Systemic Inflammatory Response Syndrome (SIRS) criteria and quick-Sepsis Related Organ Failure Assessment (q-SOFA) criteria were used to identify patients who were at an increased risk for urosepsis. Statistical analysis was performed using Fisher's exactness test, Wilcoxon rank test, and logistic regression.. Chart review identified 99 struvite stone patients treated with PCNL. Post-operatively, 40 patients were SIRS positive (≥2 criteria) and/or q-SOFA positive (score ≥2). Using SIRS as an approximation for urosepsis, longer operative times (p<0.001), higher pre-operative white blood cell counts (p=0.01), greater total stone surface area (p<0.0001), and pre-operative stenting (OR, 5.75; p=0.01) were identified as independent risk factors for urosepsis. Multivariate analysis demonstrated pre-operative stenting (OR, 1.46; p=0.01) to be a risk factor. With q-SOFA, univariable analysis found that antibiotic use within 3 months prior to a PCNL (OR, 4.44; p=0.04), medical comorbidities (OR, 4.80; p=0.02), longer operative times (p<0.001), lengthier post-operative hospitalization (p<0.01), and greater total stone surface area (p<0.0001) were risk factors for urosepsis. Multivariate analysis revealed that bladder outlet obstruction (OR, 2.74; p<0.003) and pre-operative stenting (OR, 1.27; p=0.01) significantly increased odds of being q-SOFA positive.. Several risk factors for urosepsis following PCNL for struvite stones have been identified. These risk factors should be taken into consideration in peri-operative care to mitigate the risks of urosepsis.

Topics: Adult; Aged; Female; Humans; Kidney Calculi; Male; Middle Aged; Nephrolithotomy, Percutaneous; Postoperative Complications; Retrospective Studies; Risk Factors; Sepsis; Struvite; Urinary Tract Infections

INTRODUCTION The objective of this study is to explore the association between urinary stone composition and surgical recurrence.. Patients who underwent kidney stone surgeries (between 2009-2017), were followed for > 1 year, and had ≥ 1 stone composition analyses were included in our analysis. Surgical stone recurrence (repeat surgery) was defined as the second surgery on the same kidney unit. Recurrence-free survival analysis was used.. A total number of 1051 patients were included (52.7% men, average age 59.1 +/- 15.1 years). Over 4.7 +/- 2.5 years follow up, 26.7% of patients required repeat surgery. Patients' stone compositions were calcium oxalate (66.0%), uric acid (12.2%), struvite (10.0%), brushite (5.7%), apatite (5.1%) and cystine (1.0%). Results suggested that patients with cystine stones had the highest surgical recurrence risk; brushite had the second-highest surgical recurrence risk. Struvite, uric acid, and apatite stones were at higher risk compared with calcium oxalate stones (lowest risk in our cohort). When pre and postoperative stone size was controlled, patients with a history of uric acid, brushite, and cystine stones were at higher surgical risk. After controlling clinical and demographic factors, only brushite and cystine stones were associated with higher surgical recurrence.. Patients with cystine stones had the highest surgical recurrence risk; brushite stones had the second highest surgical recurrence risk. Struvite, uric acid, and apatite stones were at higher risk compared with calcium oxalate stones. When pre and postoperative stone size, clinical and demographic factors were controlled, only those with brushite or cystine stones were at significantly higher risk of surgical recurrence.

Topics: Adult; Aged; Calcium Oxalate; Female; Humans; Kidney Calculi; Male; Middle Aged; Struvite; Uric Acid; Urinary Calculi

To determine if treatment of non-obstructing urolithiasis is effective in management of recurrent UTI.. A retrospective review was performed of patients undergoing elective management of non-struvite upper tract urinary calculi with recurrent UTI from 2009 to 2016. Recurrent UTI was defined at ≥ 3 UTI in 12 months, with symptoms and documented urine culture. Preoperative CT was performed in all patients to determine stone burden. All patients had postoperative imaging and ≥ 12 months of follow-up. Pre- and postoperative variables were between patients who had recurrent UTI after treatment versus those who did not.. 46 patients met inclusion criteria. 42 (91.3%) were female. Median age was 63.7 years (IQR 49.1, 73.4) and median total stone burden was 20 mm (IQR 14-35). Within the cohort, 20 (43.5%) underwent ureteroscopy only, 26 (56.5%) underwent PCNL ± URS, and none underwent ESWL. Median postoperative follow-up was 2.9 years (IQR 2.0, 4.3). Only five patients (10.9%) had recurrent UTI after treatment. 80% were with the preoperative pathogen. The presence of residual stone was an independent risk factor for recurrent UTI after treatment (p < 0.046). Diabetes, hypertension, immunosuppression and chronic kidney disease were not.. Stone removal for patients with recurrent UTIs was associated with a high rate of success (89.1%) in elimination of further recurrent UTIs. Residual fragments are independently associated with persistent recurrent UTIs and thus, complete stone removal is of paramount importance in treatment of this patient population.

Topics: Aged; Female; Humans; Incidence; Kidney Calculi; Male; Middle Aged; Nephrolithotomy, Percutaneous; Recurrence; Retrospective Studies; Struvite; Treatment Outcome; Ureteral Calculi; Ureteroscopy; Urinary Tract Infections

To predict the main component of pure and mixed kidney stones using dual-energy computed tomography and machine learning.. 200 kidney stones with a known composition as determined by infrared spectroscopy were examined using a non-anthropomorphic phantom on a spectral detector computed tomography scanner. Stones were of either pure (monocrystalline, n = 116) or compound (dicrystalline, n = 84) composition. Image acquisition was repeated twice using both, normal and low-dose protocols, respectively (ND/LD). Conventional images and low and high keV virtual monoenergetic images were reconstructed. Stones were semi-automatically segmented. A shallow neural network was trained using data from ND1 acquisition split into training (70%), testing (15%) and validation-datasets (15%). Performance for ND2 and both LD acquisitions was tested. Accuracy on a per-voxel and a per-stone basis was calculated.. Main components were: Whewellite (n = 80), weddellite (n = 21), Ca-phosphate (n = 39), cysteine (n = 20), struvite (n = 13), uric acid (n = 18) and xanthine stones (n = 9). Stone size ranged from 3 to 18 mm. Overall accuracy for predicting the main component on a per-voxel basis attained by ND testing dataset was 91.1%. On independently tested acquisitions, accuracy was 87.1-90.4%.. Even in compound stones, the main component can be reliably determined using dual energy CT and machine learning, irrespective of dose protocol.. • Spectral Detector Dual Energy CT and Machine Learning allow for an accurate prediction of stone composition. • Ex-vivo study demonstrates the dose independent assessment of pure and compound stones. • Lowest accuracy is reported for compound stones with struvite as main component.

Topics: Algorithms; Calcium Oxalate; Calcium Phosphates; Cysteine; Humans; Kidney Calculi; Machine Learning; Neural Networks, Computer; Phantoms, Imaging; Struvite; Tomography Scanners, X-Ray Computed; Tomography, X-Ray Computed; Uric Acid; Urinary Calculi; Xanthine

To assess the recall of a deep learning (DL) method to automatically detect kidney stones composition from digital photographs of stones.. A total of 63 human kidney stones of varied compositions were obtained from a stone laboratory including calcium oxalate monohydrate (COM), uric acid (UA), magnesium ammonium phosphate hexahydrate (MAPH/struvite), calcium hydrogen phosphate dihydrate (CHPD/brushite), and cystine stones. At least two images of the stones, both surface and inner core, were captured on a digital camera for all stones. A deep convolutional neural network (CNN), ResNet-101 (ResNet, Microsoft), was applied as a multi-class classification model, to each image. This model was assessed using leave-one-out cross-validation with the primary outcome being network prediction recall.. The composition prediction recall for each composition was as follows: UA 94% (n = 17), COM 90% (n = 21), MAPH/struvite 86% (n = 7), cystine 75% (n = 4), CHPD/brushite 71% (n = 14). The overall weighted recall of the CNNs composition analysis was 85% for the entire cohort. Specificity and precision for each stone type were as follows: UA (97.83%, 94.12%), COM (97.62%, 95%), struvite (91.84%, 71.43%), cystine (98.31%, 75%), and brushite (96.43%, 75%).. Deep CNNs can be used to identify kidney stone composition from digital photographs with good recall. Future work is needed to see if DL can be used for detecting stone composition during digital endoscopy. This technology may enable integrated endoscopic and laser systems that automatically provide laser settings based on stone composition recognition with the goal to improve surgical efficiency.

Topics: Algorithms; Calcium Oxalate; Calcium Phosphates; Cystine; Deep Learning; Humans; Image Interpretation, Computer-Assisted; Kidney Calculi; Photography; ROC Curve; Struvite; Uric Acid

Species Cissus gongylodes has been used in the traditional medicine in South America and India for the treatment of urolithiasis, biliary and inflammatory problems without any scientific evidence.. This work was developed to investigate for the first time the anti-inflammatory and anti-urolithiatic activities of leaf decoction of C. gongylodes.. Decoction was subjected to anti-inflammatory evaluation by the in vivo assay of ear oedema and quantification of the main mediators of inflammation PGE. Decoction showed in vivo anti-inflammatory activity by potent decreasing the level of both the main mediators of inflammation and dose-dependent in vitro anti-urolithiatic action by inhibition and dissolution of both type of crystals, CaOx and struvite.. Results obtained corroborate the reports of the traditional use of the decoction of Cissus gongylodes. Besides, it showed multi-target mechanisms actions, inhibition of the main inflammatory pathways, and inhibition/dissolution of the most prevalent types of crystals on urolithiasis. These actions make the decoction a promissory source to the development of new and more efficient drugs.

Topics: Animals; Anti-Inflammatory Agents; Calcium Oxalate; Cissus; Croton Oil; Crystallization; Dinoprostone; Edema; Humans; Kidney Calculi; Leukotriene B4; Male; Mice; Plant Extracts; Plant Leaves; Struvite; Tumor Necrosis Factor-alpha

Previous studies have shown that split-bolus protocols in virtual non-contrast (VNC) reconstructions of dual-energy computed tomography (DE-CT) significantly decrease radiation dose in patients with urinary stone disease. To evaluate the impact on kidney stone detection rate of stone composition, size, tube voltage, and iodine concentration for VNC reconstructions of DE-CT.. In this prospective study, 16 kidney stones of different sizes (1.2-4.5 mm) and compositions (struvite, cystine, whewellite, brushite) were placed within a kidney phantom. Seventy-two scans with nine different iodine contrast agents/saline solutions with increasing attenuation (0-1400 HU) and different kilovoltage settings (70 kV/150 kV; 80 kV/150 kV; 90 kV/150 kV; 100 kV/150 kV) were performed. Two experienced radiologists independently rated the images for the presence and absence of stones. Multivariate classification tree analysis and descriptive statistics were used to evaluate the diagnostic performance.. Classification tree analysis revealed a higher detection rate of renal calculi > 2 mm in size compared with that of renal calculi < 2 mm (84.7%; 12.7%; p < 0.001). For stones with a diameter > 2 mm, the best results were found at 70 kV/Sn 150 kV and 80 kV/Sn 150 kV in scans with contrast media attenuation of 600 HU or less, with sensitivity of 99.6% and 96.0%, respectively. A higher luminal attenuation (> 600 HU) resulted in a significantly decreased detection rate (91.8%, 0-600 HU; 70.7%, 900-1400 HU; p < 0.001). In our study setup, the detection rates were best for cystine stones.. Scan protocols in DE-CT with lower tube current and lower contrast medium attenuation show excellent results in VNC for stones larger than 2 mm but have limitations for small stones.. • The detection rate of virtual non-contrast reconstructions is highly dependent on the surrounding contrast medium attenuation at the renal pelvis and should be kept as low as possible, as at an attenuation higher than 600 HU the VNC reconstructions are susceptible to masking ureteral stones. • Protocols with lower tube voltages (70 kV/Sn 150 kV and 80 kV/Sn 150 kV) improve the detection rate of kidney stones in VNC reconstructions. • The visibility of renal stones in virtual non-contrast of dual-energy CT is highly associated with the size, and results in a significantly lower detection rate in stones below 2 mm.

Topics: Calcium Oxalate; Calcium Phosphates; Contrast Media; Cystine; Humans; Image Processing, Computer-Assisted; Iodine; Kidney Calculi; Phantoms, Imaging; Prospective Studies; Radiation Dosage; Struvite; Tomography, X-Ray Computed; Urinary Calculi

Topics: Abdominal Pain; Aged; Crystallization; Female; Humans; Kidney Calculi; Kidney Pelvis; Pyuria; Struvite; Tomography, X-Ray Computed; Urinalysis

To investigate the effect of kidney function on stone composition and urinary mineral excretion in patients undergoing surgical intervention for nephrolithiasis.. Using our institutional kidney stone database, we performed a retrospective review of stone patients who underwent surgical intervention between 2004 and 2015. Patients' demographic information, 24-hour urinary mineral excretion, and stone characteristics were reported. The patients' estimated glomerular filtration rates (eGFR) were compared with their stone compositions and 24-hour urine mineral excretions.. A statistically significant difference was noted between the groups, with uric acid stones being associated with lower eGFR and calcium phosphate stones associated with higher eGFR. No relationship could be demonstrated between eGFR and calcium oxalate or struvite stones. Patients with lower eGFR also demonstrated a statistically significant association with lower urinary pH as well as lower urinary excretion of calcium and citrate.. While various factors have been found to play significant roles in kidney stone formation and composition, our findings demonstrate a definite relationship between these and renal function. This paper highlights the fact that renal function evaluation should be considered an important component in the evaluation, counseling, and management of patients with nephrolithiasis.

Topics: Adult; Calcium; Calcium Oxalate; Calcium Phosphates; Citric Acid; Creatinine; Diabetes Mellitus; Disease Progression; Dyslipidemias; Female; Glomerular Filtration Rate; Humans; Hypertension; Incidence; Kidney Calculi; Male; Middle Aged; Renal Insufficiency, Chronic; Retrospective Studies; Struvite; Uric Acid

Topics: Humans; Kidney Calculi; Nephrostomy, Percutaneous; Retrospective Studies; Struvite

Bacterial infection has long been recognized to contribute to struvite urinary stone deposition; however, its contribution to the development of chronic kidney stones has not been extensively investigated. In the present study, we hypothesized another possible method of bacteria contributing to the formation of calcium oxalate (CaOx) that accounts for the biggest part of the kidney stone. Bacteria may play important roles by influencing renal Ca

Topics: Animals; Calcium Channels; Gene Expression Regulation; Immunity, Innate; Kidney; Kidney Calculi; Proteus Infections; Proteus mirabilis; Rats; RNA, Messenger; Struvite; Urinary Bladder; Urolithiasis

To study the association between a stone's struvite content and clinical outcomes and to determine a clinically significant cutoff for defining struvite stones.. This was a retrospective study of all patients who underwent ureteroscopy or PCNL at our institution between 2012 and 2017 and had any component of struvite in the stone analysis. Patients were divided into four groups based on percent struvite content: A (1-25%), B (26-50%), C (51-75%), and D (76-100%). Bacterial characteristics were compared between groups. Univariate and multivariate analyses were performed to evaluate the association between struvite content and postoperative SIRS. Log-rank test was used to compare between the four groups' recurrence rates.. A total of 123 patients were included in the study. Positive preoperative urine culture was found in 31%, 81%, 87%, and 90% of patients from group A, B, C, and D, respectively. E. Coli was the most common pathogen in group A (54%), while Proteus was the most common pathogen in groups C (53%) and D (47%). Enterococci isolation rates remained similar between groups A-D, ranging from 23 to 33%. Postoperative SIRS occurred in 2.4%, 21.3%, 26.7%and 47.4% of the patients from groups A, B, C, and D, respectively, and was associated with struvite content and age on multivariate analysis. Increasing struvite content was associated with higher 2-year recurrence rate.. Higher struvite content is associated with a higher frequency of traditional urea splitting bacteria in urine culture, higher risk for postoperative SIRS, and higher recurrence rate. Struvite content greater than 25% can be used to define a clinically significant struvite stone.

Topics: Aged; Bacteriuria; Enterobacteriaceae; Enterococcus; Escherichia coli; Female; Humans; Kidney Calculi; Klebsiella; Male; Middle Aged; Nephrolithotomy, Percutaneous; Preoperative Period; Proteus; Recurrence; Retrospective Studies; Struvite; Systemic Inflammatory Response Syndrome; Ureteroscopy; Urine

To evaluate the association of clinical factors on outcomes in patients with spinal cord injury (SCI) undergoing ureteroscopy. Immobility, recurrent urinary tract infection, and lower urinary tract dysfunction contribute to renal stone formation in patients with SCI. Ureteroscopy is a commonly utilized treatment modality; however, surgical complication rates and outcomes have been poorly defined. Evidence guiding safe and effective treatment of stones in this cohort remains scarce.. Records were retrospectively reviewed for patients with SCI who underwent ureteroscopy for kidney stones from 1996 to 2014 at a single institution. Multivariate relationships were evaluated using a general estimating equation model.. Forty-six patients with SCI underwent a total of 95 ureteroscopic procedures. After treatment, stone-free rate was 17% and 20% with <2-mm fragments. The complication rate was 21%. On multivariate analysis, SCI in cervical (C) levels was associated with higher risk of complications (C3: odds ratio [OR] 3.83, 95% confidence interval [CI] 2.17-6.98; C6: OR 3.83, 95% CI 1.08-13.53). American Spinal Injury Association Scale A classification was associated with a lower probability of stone-free status (OR 0.16, 95% CI 0.03-0.82). Patients averaged 2.2 procedures yet more procedures were associated with lower stone-free status (OR 0.83, 95% CI 0.03-0.32). Chronic obstructive pulmonary disease and bladder management modality were not associated with stone-free status or complications.. In patients with SCI, higher injury level and complete SCI were associated with worse stone clearance and more complications. Stone-free rate was 17%. Overall, flexible ureteroscopy is a relatively safe procedure in this population. Alternative strategies should be considered after failed ureteroscopy.

Topics: Adult; Aged; Apatites; Cardiovascular Diseases; Comorbidity; Diabetes Mellitus; Female; Humans; Kidney Calculi; Lithotripsy, Laser; Male; Middle Aged; Multivariate Analysis; Operative Time; Postoperative Complications; Renal Insufficiency, Chronic; Respiratory Tract Diseases; Spinal Cord Injuries; Struvite; Treatment Outcome; Ureteroscopy; Urinary Bladder, Neurogenic; Urinary Tract Infections

We sought to investigate the association between renal stone composition and percutaneous nephrolithotomy outcomes in pediatric patients and define the characterization of the stone composition.. The data of 1157 children who underwent percutaneous nephrolithotomy between 1991 and 2012 were retrieved from the multicenter database of the Turkish Pediatric Urology Society. The study population comprised 359 children (160 girls, 199 boys) with stone analyses. Patients were divided into five groups according to the stone composition [group 1: calcium oxalate; group 2: calcium phosphate; group 3: infection stones (magnesium ammonium phosphate, ammonium urate); group 4: cystine; group 5: uric acid, xanthine stones].. Patient characteristics, perioperative, postoperative, and stone characteristics were compared considering the stone composition. There were no significant differences between the groups concerning age, sex, side involved, preoperative hematocrit levels, and solitary renal unit. Patients with cystine stones were more likely to have a history of stone treatment. Groups 2 and 5 had mostly solitary stones. However, group 3 had staghorn stone more often, and group 4 frequently had multiple stones. Overall stone-free rate (79.4%) was similar among the groups. Although stone composition was related to blood transfusion and prolonged operative and fluoroscopy screening times on univariate analysis, it was not a significant predictor of them on multivariate analysis.. Stone composition was not a predictor of outcomes of pediatric percutaneous nephrolithotomy. However, cystine and infection stones, which are larger and filled multiple calyxes due to the nature of stone forming, were more challenging cases that need multiple tracts.

Topics: Adolescent; Blood Transfusion; Calcium Oxalate; Calcium Phosphates; Child; Child, Preschool; Cystine; Databases, Factual; Female; Fluoroscopy; Humans; Infant; Kidney Calculi; Kidney Calices; Male; Multivariate Analysis; Nephrolithotomy, Percutaneous; Operative Time; Retrospective Studies; Staghorn Calculi; Struvite; Treatment Outcome; Turkey; Uric Acid; Xanthine

It is a fact that recurrence of urinary stones is a common medical problem. One of the key factors used in determining the risk of urinary stone-formation is the urine relative saturation in the major constituents of lithiasis. Nomograms were developed in the 1970's to estimate the relative saturation of urine. We present here easy-to-use mathematical equations derived from these nomograms. These equations can be integrated directly in the LIS of any laboratories, and can be used as a tool in the treatment and prevention of recurrent stone-formation.

Topics: Algorithms; Ammonia; Calcium; Calcium Oxalate; Calcium Phosphates; Cysteine; Cystine; Hospitals, Urban; Humans; Hydrogen-Ion Concentration; Kidney Calculi; Magnesium; Models, Biological; Oxalic Acid; Phosphates; Quebec; Recurrence; Remission Induction; Risk Factors; Struvite; Uric Acid; Urinary Calculi

To examine urine and stone bacteriology of struvite stone formers in a large cohort of patients undergoing percutaneous nephrolithotomy (PCNL).. A total of 1191 patients, with stone and urine cultures, treated with PCNL for renal calculi were included in the study. Statistical differences were assessed using Mann-Whitney U and T-tests.. Stone cultures were positive in 72% of patients with struvite stones. Urea-splitting organisms accounted for only half of the positive stone cultures. Enterococcus (9/50, 18%), Proteus (9/50, 18%), and Escherichia coli (6/50, 12%) were the most commonly identified organisms. Notably, two-thirds of struvite formers with negative stone culture had at least one positive culture for a urea-splitting organism on urine culture going back 1 year from the time of surgery. A majority (67%) of struvite stone cultures were found to be resistant to first- and second-generation cephalosporins.. The bacteriology of struvite stones has shifted away from traditional urea-splitting organisms and antibiotic coverage must be expanded to include organisms such as Enterococcus that do not respond to cephalosporins. Causative organisms may be found by going back in time to identify the initial organism that could have induced struvite stone formation to inform preventative therapy.

Topics: Adult; Enterococcus; Escherichia coli; Escherichia coli Infections; Female; Humans; Kidney Calculi; Male; Middle Aged; Nephrolithotomy, Percutaneous; Proteus; Proteus Infections; Sepsis; Streptococcal Infections; Struvite; Tertiary Care Centers; Urea; Urinalysis

Computed Tomography (CT) is considered the gold-standard for the pre-operative evaluation of urolithiasis. However, no Hounsfield (HU) variable capable of differentiating stone types has been clearly identified. The aim of this study is to assess the predictive value of HU parameters on CT for determining stone composition and outcomes in percutaneous nephrolithotomy (PCNL).. Seventy seven consecutive cases of PCNL between 2011 and 2016 were divided into 4 groups: 40 (52%) calcium, 26 (34%) uric acid, 5 (6%) struvite and 6 (8%) cystine stones. All images were reviewed by a single urologist using abdomen/bone windows to evaluate: stone volume, core (HUC), periphery HU and their absolute difference. HU density (HUD) was defined as the ratio between mean HU and the stone's largest diameter. ROC curves assessed the predictive power of HU for determining stone composition/stone-free rate (SFR).. No differences were found based on the viewing window (abdomen vs bone). Struvite stones had values halfway between hyperdense (calcium) and low-density (cystine/uric acid) calculi for all parameters except HUD, which was the lowest. All HU variables for medium-high density stones were greater than low-density stones (p < 0.001). HUC differentiated the two groups (cut-off 825 HU; specificity 90.6%, sensitivity 88.9%). HUD distinguished calcium from struvite (mean ± SD 51 ± 16 and 28 ± 12 respectively; p = 0.02) with high sensitivity (82.5%) and specificity (80%) at a cut-off of 35 HU/mm. Multivariate analysis revealed HUD ≥ 38.5 HU/mm to be an independent predictor of SFR (OR = 3.1, p = 0.03). No relationship was found between HU values and complication rate.. HU parameters help predict stone composition to select patients for oral chemolysis. HUD is an independent predictor of residual fragments after PCNL and may be fundamental to categorize it, driving the imaging choice at follow-up.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Analysis of Variance; Calcium; Cross-Sectional Studies; Cystine; Female; Humans; Kidney Calculi; Male; Middle Aged; Nephrolithotomy, Percutaneous; Operative Time; Postoperative Complications; Retrospective Studies; ROC Curve; Sensitivity and Specificity; Struvite; Tomography, X-Ray Computed; Uric Acid; Young Adult

Previous studies suggested that patients with pure struvite calculi rarely have underlying metabolic abnormalities. Therefore, most of these patients do not undergo metabolic studies. We report our experience with these patients and their response to directed medical therapy. Between 1/2005 and 9/2012, 75 patients treated with percutaneous nephrolithotomy for struvite stones were identified. Of these, 7 had pure struvite stones (Group 1), 32 had mixed struvite stones (Group 2), both with metabolic evaluation, and 17 had pure struvite stones without metabolic evaluation (Group 3). The frequency of metabolic abnormalities and stone activity (defined as stone growth or stone-related events) was compared between groups. The median age was 55 years and 64 % were female. No significant difference in race, infection history, family history, stone location or volume existed between groups. Metabolic abnormalities were found in 57 % of Group 1 and 81 % of Group 2 patients. A similar proportion of Group 1 and 2 patients received modification to or continuation of metabolic therapy, whereas no Group 3 patients received any directed therapy. In patients with >6 months follow-up, the stone activity rate between Groups 1 and 2 appeared similar whereas Group 3 trended towards higher stone activity rate. Metabolic abnormalities in pure struvite stone formers appear to be more common than previously reported. Directed medical therapy in these patients may reduce stone activity. The role of metabolic evaluation and directed medical therapy needs reconsideration in patients with pure struvite stones.

Topics: Adult; Female; Humans; Kidney Calculi; Lithotripsy; Male; Middle Aged; Nephrostomy, Percutaneous; Retrospective Studies; Struvite

The optimal management of lower pole kidney (LPK) stones in children is controversial. The aim of this study was to determine the outcomes of children with asymptomatic isolated LPK stones smaller than 10 mm during follow-up.. A total of 242 patients with 284 stones presenting at our institution between June 2004 and December 2014 with an asymptomatic, single LPK stone with a diameter of <10 mm were enrolled in the study. All children were assigned to receive first-line therapy and then categorized according to the need for medical intervention. Age, gender, stone laterality, stone size and type, associated urinary tract problems, and uncontrolled metabolic status were assessed as predictive factors of medical treatment for small (<10 mm) asymptomatic LPK stones. Stone-free rates were compared between interventions.. The mean age and mean stone size were 9.4 ± 1.9 years and 7.4 ± 0.6 mm at admission, respectively. Stone progression rate was 61.2%, and the mean time for intervention was 19.2 ± 4.6 months. Flexible ureterorenoscopy (n = 68) or micro-percutaneous nephrolithotomy (n = 4) were performed for 72 stones (25.4%; group 1), and extracorporeal shock wave lithotripsy was performed for 102 stones (35.9%; group 2). The stone-free rates were 81.8 and 79.3% in group 1 and 2, respectively (p > 0.05). The remaining asymptomatic stones (110, 38.8%; group 3) were managed by continued observation, and at the end of the observation time (mean 40.8 ± 20.8 months) the spontaneous passage rate was 9.1% in this group. In the multivariate analysis, stone size of >7 mm, concurrent renal anomalies, and stones composed of magnesium ammonium phosphate (struvite) and cystine were statistically significant predictors of the need for intervention.. Children with stones larger than 7 mm, renal anomalies, or stones composed of metabolically active cystine or struvite are more likely to require intervention, and those with asymptomatic LPK stones smaller than 10 mm can be managed by continued observation.

Topics: Adolescent; Age Factors; Child; Child, Preschool; Cystine; Female; Humans; Infant; Kidney Calculi; Lithotripsy; Male; Nephrolithotomy, Percutaneous; Sex Factors; Struvite; Treatment Outcome; Urologic Diseases; Watchful Waiting

Struvite stones have been associated with significant morbidity and mortality, yet there has not been a report on the medical management of struvite stones in almost 20 years. We report on the contemporary outcomes of the surgical and medical management of struvite stones in a contemporary series.. A retrospective review of patients who were treated with percutaneous nephrolithotomy (PCNL) for struvite stones at Duke University Medical Center between January 2005 and September 2012 identified a total of 75 patients. Of these, 43 patients had adequate follow-up and were included in this analysis. Stone activity, defined as either stone recurrence or stone-related events, and predictors of activity were evaluated after combined surgical and medical treatment.. The study included 43 patients with either pure (35%) or mixed (65%) struvite stones with a median age of 55±15 years (range 21-89 years). The stone-free rate after PCNL was 42%. Stone recurrence occurred in 23% of patients. Postoperatively, 30% of patients had a stone-related event, while 60% of residual stones remained stable with no growth after a median follow-up of 22 months (range 6-67 mos). Kidney function remained stable during follow-up. Independent predictors of stone activity included the presence of residual stones >0.4 cm(2), preoperative large stone burden (>10 cm(2)), and the presence of medical comorbidities (P<0.05).. Struvite stones can be managed safely with PCNL followed by medical therapy. The majority of patients with residual fragments demonstrated no evidence of stone growth on medical therapy. With careful follow-up and medical management, kidney function can be maintained and stone morbidity can be minimized. Initial large stone burden, residual stones after surgery, and associated medical comorbidities may have deleterious effect on stone recurrence or residual stone-related events.

Topics: Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Calcium Citrate; Chlorthalidone; Comorbidity; Diuretics; Enzyme Inhibitors; Female; Humans; Hydroxamic Acids; Kidney Calculi; Male; Middle Aged; Nephrostomy, Percutaneous; Postoperative Complications; Potassium Citrate; Recurrence; Retrospective Studies; Sodium Bicarbonate; Struvite; Treatment Outcome; Young Adult

We present in this paper accurate and reliable Raman and IR spectral identification of mineral constituents in nine samples of renal calculi (kidney stones) removed from patients suffering from nephrolithiasis. The identified mineral components include Calcium Oxalate Monohydrate (COM, whewellite), Calcium Oxalate Dihydrate (COD, weddellite), Magnesium Ammonium Phosphate Hexahydrate (MAPH, struvite), Calcium Hydrogen Phosphate Dihydrate (CHPD, brushite), Pentacalcium Hydroxy Triphosphate (PCHT, hydroxyapatite) and Uric Acid (UA). The identification is based on a satisfactory assignment of all the observed IR and Raman bands (3500-400c m(-1)) to chemical functional groups of mineral components in the samples, aided by spectral analysis of pure materials of COM, MAPH, CHPD and UA. It is found that the eight samples are composed of COM as the common component, the other mineral species as common components are: MAPH in five samples, PCHT in three samples, COD in three samples, UA in three samples and CHPD in two samples. One sample is wholly composed of UA as a single component; this inference is supported by the good agreement between ab initio density functional theoretical spectra and experimental spectral measurements of both sample and pure material. A combined application of Raman and IR techniques has shown that, where the IR is ambiguous, the Raman analysis can differentiate COD from COM and PCHT from MAPH.

Topics: Calcium Oxalate; Calcium Phosphates; Durapatite; Humans; Kidney Calculi; Magnesium Compounds; Phosphates; Spectroscopy, Fourier Transform Infrared; Spectrum Analysis, Raman; Struvite; Uric Acid

Determine stones composition of the upper urinary tract in the eastern region of Algeria.. Our study focuses on a set of 359 stones of the upper urinary tract collected between January 2007 and December 2012 at hospitals in the eastern region of Algeria and analyzed by Fourier transform infrared spectroscopy.. The male/female ratio was only 1.32. Calcium oxalate prevailed in 68.5% of stones and 49.3% of nuclei, mainly as whewellite (51.8% of stones and 37.9% of nuclei vs 16.7% and 11.4% respectively for weddellite). Carbapatite prevailed in 15% of stones and 29.8% of nuclei. The struvite, identified in 11.1% of calculi, prevailed in 3.9% of stones and 3.1% of nuclei. Among purines, uric acid prevailed with frequencies quite close to 8.9% and 7% respectively in the stone and in the nucleus while the ammonium urate prevailed in only 0.3% of stones and 3.3% of nuclei. The cystine frequency was 3.6% in both stone and nucleus. The frequency of stone with umbilication was 26.2%. Whewellite was the main component of umbilicated stones with Randall's plaque.. Our results suggest that stones of the urinary tract in the Algerian east region resemble those observed in industrialized countries. Some features such as stones location, the whewellite prevalence, the frequencies of main components in both the stone and the nucleus as well as the formation of stones on renal papilla confirm this trend.. 4.

Topics: Adult; Aged; Algeria; Antioxidants; Apatites; Calcium Oxalate; Female; Hemostatics; Hospitals; Humans; Kidney Calculi; Magnesium Compounds; Male; Middle Aged; Phosphates; Prevalence; Retrospective Studies; Risk Factors; Sex Distribution; Spectroscopy, Fourier Transform Infrared; Struvite; Uric Acid

To describe the endoscopic characteristics of renal papillae in struvite stone formers (SFs).. From 2009 to 2014, patients undergoing percutaneous nephrolithotomy were prospectively enrolled in our study. Endoscopic analysis and biopsy of papillae were performed to demonstrate the presence and percentage surface area (SA) of Randall's plaque or ductal plug. Comparison with idiopathic calcium oxalate (CaOx) SF and non-SF controls was performed.. We identified 29 struvite SFs to compare with 90 idiopathic CaOx SFs and 17 controls. On endoscopic mapping, 28 struvite SFs (97%) demonstrated Randall's plaque and 9 (31%) had plugging. The average mean SA of Randall's plaque in struvite SF (1.5 ± 1.4%) was less than CaOx SFs (3.7 ± 4.3%, P  =  .0018) and similar to controls (1.7 ± 2.7%, P  =  .76). Average mean plug SA was similar between struvite SFs, CaOx SFs, and controls. On metabolic assessment, 83% of struvite SFs had at least one urine abnormality, with urinary uric acid and oxalate levels significantly higher among struvite SFs compared to controls (P  =  .002). Despite lack of active urinary tract infection, interstitial inflammation was more prevalent in struvite SFs compared to CaOx SFs (43.5% vs 7.3%, P  =  .0001).. Our findings suggest a limited role for Randall's plaque in struvite stone formation. Struvite SFs have less plaque formation than CaOx SFs, but demonstrate evidence of severe parenchymal inflammation compared to other SFs. The role of this prominent interstitial inflammation requires further study.

Topics: Aged; Female; Humans; Kidney Calculi; Magnesium Compounds; Male; Middle Aged; Phosphates; Prospective Studies; Risk Factors; Struvite; Ureteroscopy

We aimed to investigate a multiparametric approach using single-source dual-energy computed tomography (ssDECT) for the characterization of renal stones.. ssDECT scans were performed at 80 and 140 kVp on 32 ex vivo kidney stones of 3-10 mm in a phantom. True composition was determined by infrared spectroscopy to be uric acid (UA; n = 14), struvite (n = 7), cystine (n = 7), or calcium oxalate monohydrate (n = 4). Measurements were obtained for up to 52 variables, including mean density at 11 monochromatic keV levels, effective Z, and multiple material basis pairs. The data were analyzed with five multiparametric algorithms. After omitting 8 stones smaller than 5 mm, the remaining 24-stone dataset was similarly analyzed. Both stone datasets were also analyzed with a subset of 14 commonly used variables in the same fashion.. For the 32-stone dataset, the best method for distinguishing UA from non-UA stones was 97% accurate, and for distinguishing the non-UA subtypes was 72% accurate. For the 24-stone dataset, the best method for distinguishing UA from non-UA stones was 100% accurate, and for distinguishing the non-UA subtypes was 75% accurate.. Multiparametric ssDECT methods can distinguish UA from non-UA stones of 5 mm or larger with 100% accuracy. The best model to distinguish the non-UA renal stone subtypes was 75% accurate. Further refinement of this multiparametric approach may increase the diagnostic accuracy of separating non-UA subtypes and assist in the development of a clinical paradigm for in vivo use.

Topics: Calcium Oxalate; Humans; Kidney Calculi; Phantoms, Imaging; Struvite; Tomography, X-Ray Computed; Uric Acid

To determine the natural history of residual fragments (RF) after percutaneous nephrolithotomy in long-term patient follow-up and to identify possible predictive factors for future intervention.. We assessed all patients from 2006 to 2013 with postoperative computed tomography scan revealing RF, who did not undergo second-look nephroscopy or immediate ancillary procedures, and with at least 12 months of clinical follow-up. We evaluated factors associated with clinical, radiological, and surgical outcomes. Kaplan-Meier curves were used to calculate the proportion of asymptomatic and treatment-free patients during follow-up.. From 781 percutaneous nephrolithotomies performed, 202 patients underwent postoperative computed tomography scan and 44 patients with residual stones were included in the analysis. Mean follow-up was 57.9 months. A total of 24 patients (54.5%) developed at least 1 clinical outcome, and 32 (72.7%) patients had a surgical intervention. Only 4 patients had radiological evidence of stone passage. Multivariate analysis found that RF >4 mm and struvite or apatite stones were significant predictors for surgical intervention. The 5-year estimated probability to remain intervention free was 29%.. Despite the size of the RF, the vast majority of patients required an intervention during long-term follow-up. We identified that RFs of diameter >4 mm associate with the need for a surgical therapy, but the rate of clinical events was not affected by the size or location of the stones. Struvite or apatite composition stones had an increased risk of intervention during follow-up. Spontaneous passage was an uncommon event in this cohort.

Topics: Apatites; Female; Flank Pain; Follow-Up Studies; Humans; Kidney Calculi; Male; Middle Aged; Nephrolithotomy, Percutaneous; Postoperative Period; Probability; Renal Colic; Reoperation; Retrospective Studies; Risk Factors; Struvite; Time Factors; Tomography, X-Ray Computed

In this study data on composition of uroliths collected from cats and epidemiologic data of affected cats in Switzerland from 2002 to 2009 are summarised. Of 884 stones analysed 50% (n=441) were composed of calcium oxalate, 45% (n=398) of struvite, 3% (n=18) of ammonium urate, 1% (n=12) were mixed stones, 1% (n=9) were composed of silica, 3 stones were solidified blood, 2 consisted of cystine and 1of xanthine. 40% of the ureteral stones were composed of struvite. Domestic cats had significantly less calcium oxalate stones compared to British Shorthair or Persian cats. Cats with calcium oxalate stones were older and cats with struvite stones were younger than other affected cats. Female and male cats were equally affected with stones. Compared to studies from other countries, in Switzerland silica stones occurred more often and ureteral stones were more often composed of Struvite. The present study shows that occurrence and prevalence of urinary calculi of cats from Switzerland exhibited only slight differences to studies from other countries.. In dieser Arbeit werden Daten zur Zusammensetzung von Harnsteinen bei Katzen und epidemiologische Daten dieser Katzen in der Schweiz in den Jahren 2002 bis 2009 zusammengefasst. Von allen 884 analysierten Steinen bestanden 50% (n=441) aus Kalziumoxalat, 45% (n=398) aus Struvit, 3% (n=18) aus Ammoniumurat, 1% (n=12) waren gemischte Steine, 1% (n=9) bestanden aus Silikat, 3 Steine waren aus verfestigtem Blut, 2 bestanden aus Cystin und einer aus Xanthin. 40% der Uretersteine bestanden aus Struvit. Hauskatzen hatten signifikant seltener Kalziumoxalatsteine als British Shorthair oder Perser Katzen. Katzen mit Kalziumoxalatsteinen waren älter und Katzen mit Struvitsteinen waren jünger als andere betroffene Katzen. Weibliche und männliche Katzen waren gleich häufig von Steinen betroffen. Im Vergleich zu Studien aus anderen Ländern, kamen in der Schweiz Silikatsteine häufiger vor und Uretersteine bestanden häufiger aus Struvit. Die vorliegende Untersuchung zeigt, dass Vorkommen und Häufigkeit von Harnsteinen bei Katzen in der Schweiz nur geringe Unterschiede zu Studien aus anderen Ländern aufweisen.. Dans le présent travail, on résume les données relatives à la composition des calculs urinaires chez les chats en Suisse ainsi que les données épidémiologiques de ces animaux entre 2002 et 2009. Parmi les 884 calculs analysés, 50% (n=441) étaient composés d’oxalate de calcium, 45% (n=398) de struvite, 3% (n=18) d’urate d’ammonium, 1% (n=12) étaient des calculs mixtes 1% (n=9) se composaient de silicate, 3 calculs étaient formé de sang aggloméré, 2 étaient composés de cystine et un de xanthine. 40% des calculs urétraux se composaient de struvite. Les chats de maison avaient significativement moins de calculs d’oxalate de calcium que les British Shorthair ou les Persans. Les chats présentant des calculs d’oxalate de calcium étaient plus âgés et ceux présentant des struvites plus jeunes que tous les autres chats atteints. Les femelles et les mâles souffraient de calculs de façon équivalente. En comparaison avec des études menées dans d’autres pays, les calculs de silicate étaient plus fréquents en Suisse et les calculs urétraux se composaient plus souvent de struvite. Cette étude démontre que la survenue et la fréquence de calculs urinaires chez les chats en Suisse ne présente que peu de différence avec les études faites dans d’autres pays.. In questo studio vengono riassunti i dati sulla composizione degli uroliti nei gatti e i dati epidemiologici degli stessi in Svizzera dal 2002 al 2009. Il 50% (n=441) degli 884 calcoli analizzati era composto di ossalato di calcio, il 45% (n=398) di struvite, il 3% (n=18) di urato di ammonio, l’1% (n=12) di calcoli misti, l’1% (n=9) di silicati, 3 calcoli erano di sangue coagulato, 2 di cisteina e 1 di xantina. Il 40% dei calcoli nell’uretere erano composti da struvite. I gatti domestici avevano significativamente meno calcoli composti da ossalato di calcio che il British Shorthair o i gatti persiani. Paragonando i gatti colpiti, quelli affetti da calcoli di ossalato di calcio erano anziani mentre quelli con calcoli di struvite giovani. Il sesso dei gatti non era un fattore che influenzava più o meno la presenza di calcoli. Rispetto agli studi di altri Paesi, in Svizzera i calcoli urinari più comuni sono composti da silicati mentre quelli dell’uretere da struvite. Il presente studio dimostra che la prevalenza e l’incidenza dei calcoli urinari nei gatti in Svizzera è solo di poco differente che in altri Paesi.

Topics: Animals; Calcium Oxalate; Cat Diseases; Cats; Female; Kidney Calculi; Male; Silicon Dioxide; Struvite; Switzerland; Uric Acid; Urolithiasis

Fifty-four patients with infected renal lithiasis underwent complete metabolic evaluation searching for underlying factors contributing to stone formation including urine analysis and culture. Metabolic abnormalities were significantly more present in patients with mixed infected stones (struvite+/-apatite and calcium oxalate) than in patients with pure infected stones (struvite+/-carbonate apatite): hypercalciuria in 40%, hyperoxaluria in 34% and hyperuricosuria in 28% (p < 0.05). Urinary excretion of citrate was low in both groups without statistically significant difference (238+/-117 mg/24 h vs 214+/-104 mg/24/h, t = 0.72, p = 0.5). The few metabolic abnormalities present in patients with pure infected stones should suggest that urinary tract infection could change the urine chemistry in a lithogenic direction and be only cause of stone formation.

Topics: Adolescent; Adult; Aged; Apatites; Calcium Oxalate; Citric Acid; Female; Follow-Up Studies; Humans; Hypercalciuria; Hyperoxaluria; Kidney Calculi; Male; Middle Aged; Nephrolithiasis; Struvite; Uric Acid; Young Adult

We recently reported that occupational exposure to trimethyltin (TMT) is a risk factor for developing kidney stones. To further examine the association between TMT exposure and the formation of kidney stones, we conducted a 180-day animal study and exposed the randomly grouped Sprague-Dawley (SD) rats to TMT in the drinking water at doses of 0, 8.2, 32.8 and 131.3 µg kg(-1) day(-1). Transient behavioral changes were observed in the high-dose group during the first 2 weeks of exposure. TMT exposure led to a significant dose-dependent inhibition of renal H(+)/K(+)-ATPase and an increase in urinary pH. In comparison to no kidney stones being identified in the control and the lowest dose group, 1 rat in the 32.8 µg kg(-1) day(-1) dose group and 3 out of 9 rats in the 131.3 µg kg(-1) day(-1) dose group were found to have stones in the kidney/urinary tract. Pathological analysis showed that more wide spread calcium disposition was observed in kidneys of rats with TMT exposure compared with the rats in the control group. However, X-ray diffraction (XRD) analysis found that the kidney stones were mainly composed of struvite with the formula: NH4MgPO4 6H2O, while calcium-containing components were also detected. Together, this study further demonstrates through animal studies that chronic exposure to a relatively low level of TMT induces nephrotoxicity and increases the risk for developing kidney stones.

Topics: Animals; Dose-Response Relationship, Drug; Female; Gas Chromatography-Mass Spectrometry; Hydrogen-Ion Concentration; Kidney; Kidney Calculi; Magnesium Compounds; Male; Phosphates; Rats; Rats, Sprague-Dawley; Struvite; Trimethyltin Compounds; X-Ray Diffraction

The goal of this study was to analyze the effect of stone composition on the efficacy of retrograde intrarenal surgery (RIRS) with kidney stones of 1-3 cm, 1-2 cm, and 2-3 cm in diameter.. We undertook a retrospective analysis of 74 patients with kidney stones who underwent RIRS. The patients were divided into two groups based on stone composition: Group I (n=47) (calcium oxalate monohydrate and calcium phosphate) was the hard to fragment stone group and group II (n=27) (calcium oxalate dihydrate, magnesium ammonium phosphate, and uric acid) was the easy to fragment stone group. Forty-six patients with kidney stones 1 to 2 cm in diameter were divided into group A (n=30) (smaller than 20 mm, hard to fragment stones) and group B (n=16) (smaller than 20 mm, easy to fragment stones). Twenty-eight patients with stones 2 to 3 cm in diameter were divided into group C (n=17) (larger than 20 mm, hard to fragment stones) and group D (n=11) (larger than 20 mm, easy-to-crush stones).. The stone clearance rates of group I and group II were 66.0% and 88.9%, respectively (P<0.05). The stone clearance rates of group A and group B were 73.3% and 100% (P<0.05). The stone clearance rates of group C and group D were 52.9% and 72.7%, respectively.. Stone composition has a significant impact on the efficacy of RIRS in the management of 1 to 3 cm kidney stones. For 2-3 cm calcium oxalate dihydrate stones, uric acid stones, and magnesium ammonium phosphate stones, the outcome of RIRS treatment was relatively good, and RIRS is recommended.

Topics: Adult; Calcium Oxalate; Calcium Phosphates; Female; Humans; Kidney; Kidney Calculi; Magnesium Compounds; Male; Middle Aged; Nephrolithiasis; Phosphates; Retrospective Studies; Struvite; Treatment Outcome; Ureteroscopy; Uric Acid

This study aimed to assess the accuracy of low-dose dual-energy computed tomography (DECT) in predicting the composition of urinary calculi.. A total of 52 patients with urinary calculi were scanned with a 128-slice dual-source DECT scanner by use of a low-dose protocol. Dual-energy (DE) ratio, weighted average Hounsfield unit (HU) of calculi, radiation dose, and image noise levels were recorded. Two radiologists independently rated study quality. Stone composition was assessed after extraction by Fourier transform infrared spectroscopy (FTIRS). Analysis of variance was used to determine if the differences in HU values and DE ratios between the various calculus groups were significant. Threshold cutoff values to classify the calculi into separate groups were identified by receiver operating characteristic curve analysis.. A total of 137 calculi were detected. FTIRS analysis differentiated the calculi into five groups: uric acid (n=17), struvite (n=3), calcium oxalate monohydrate and dihydrate (COM-COD, n=84), calcium oxalate monohydrate (COM, n=28), and carbonate apatite (n=5). The HU value could differentiate only uric acid calculi from calcified calculi (p<0.001). The DE ratio could confidently differentiate uric acid, struvite, calcium oxalate, and carbonate apatite calculi (p<0.001) with cutoff values of 1.12, 1.34, and 1.66, respectively, giving >80% sensitivity and specificity to differentiate them. The DE ratio could not differentiate COM from COM-COD calculi. No study was rated poor in quality by either of the observers. The mean radiation dose was 1.8 mSv.. Low-dose DECT accurately predicts urinary calculus composition in vivo while simultaneously reducing radiation exposure without compromising study quality.

Topics: Adult; Apatites; Calcium Oxalate; Female; Humans; Image Interpretation, Computer-Assisted; Kidney Calculi; Magnesium Compounds; Male; Middle Aged; Phosphates; Prospective Studies; Radiation Dosage; Struvite; Tomography, X-Ray Computed; Ureteral Calculi; Uric Acid; Waist Circumference; Young Adult

To determine the variation in kidney stone composition and its association with risk factors and recurrence among first-time stone formers in the general population.. Medical records were manually reviewed and validated for symptomatic kidney stone episodes among Olmsted County, Minnesota, residents from January 1, 1984, through December 31, 2012. Clinical and laboratory characteristics and the risk of symptomatic recurrence were compared between stone compositions.. There were 2961 validated first-time symptomatic kidney stone formers. Stone composition analysis was obtained in 1508 (51%) at the first episode. Stone formers were divided into the following mutually exclusive groups: any brushite (0.9%), any struvite (0.9%), any uric acid (4.8%), and majority calcium oxalate (76%) or majority hydroxyapatite (18%). Stone composition varied with clinical characteristics. A multivariable model had a 69% probability of correctly estimating stone composition but assuming calcium oxalate monohydrate stone was correct 65% of the time. Symptomatic recurrence at 10 years was approximately 50% for brushite, struvite, and uric acid but approximately 30% for calcium oxalate and hydroxyapatite stones (P<.001). Recurrence was similar across different proportions of calcium oxalate and hydroxyapatite (P for trend=.10). However, among calcium oxalate stones, 10-year recurrence rate ranged from 38% for 100% calcium oxalate dihydrate to 26% for 100% calcium oxalate monohydrate (P for trend=.007).. Calcium stones are more common (93.5% of stone formers) than has been previously reported. Although clinical and laboratory factors associate with the stone composition, they are of limited utility for estimating stone composition. Rarer stone compositions are more likely to recur.

Topics: Adult; Aged; Calcium Oxalate; Female; Humans; Kidney Calculi; Magnesium Compounds; Male; Middle Aged; Minnesota; Phosphates; Prevalence; Prognosis; Recurrence; Risk Assessment; Risk Factors; Struvite; Symptom Assessment; Uric Acid

To determine kidney stone composition in children and to correlate stone fractions with urinary pH and metabolic urinary risk factors.. We studied 135 pediatric patients with upper urinary tract lithiasis in whom excreted or extracted stones were available for analyses. Composition of stones was analyzed. A 24-hour urine assessment included volume, pH and daily excretions of calcium, oxalate, uric acid, cystine, creatinine, phosphate, magnesium and citrate.. Calcium oxalate was the major component of 73% stones, followed by struvite (13%) and calcium phosphate (9%). Uric acid was present in almost half of stones, but in rudimentary amounts. The calcium oxalate content in calculi showed a strong relationship with calciuria, and moderate association with oxaluria, magnesuria and acidification of urine. The percent content of struvite presented reverse and lower correlations with regard to the above parameters. Calcium phosphate stone proportion had low associations with urinary risk factors.. Calciuria, oxaluria, magnesuria and low urine pH exerted the biggest influence on calcium oxalate content in pediatric renal stones. Relationships of urinary risk factors with calculi calcium phosphate content were of unclear significance. Urinary citrate excretion did not significantly correlate with kidney stone composition in children.

Topics: Adolescent; Calcium Oxalate; Calcium Phosphates; Child; Female; Humans; Hydrogen-Ion Concentration; Kidney Calculi; Magnesium Compounds; Male; Phosphates; Risk Factors; Struvite

Sialoliths are common in the submandibular gland and its duct system, although their exact cause of formation is still a matter of debate. The aims of this study were to: (a) analyze sialoliths ultrastructurally, and to determine the role of foreign bodies or organic materials in the formation of sialolith nuclei; and (b) compare nephroliths with sialoliths ultrastructurally.. Three sialoliths and two nephroliths were analyzed ultrastructurally by a scanning electron microscope and X-ray diffractometer.. The main structures of the sialoliths were found to be hydroxyapatite crystals. No organic cores were observed in the central parts of the sialoliths. In nephroliths, calcium oxalate, calcium phosphate, and struvite crystals were found. The energy-dispersive X-ray microanalysis found that sialoliths and nephroliths were predominantly composed of elements comprising calcium, phosphorous, magnesium, sodium, chloride, silicon, iron, and potassium.. Sialoliths in the submandibular salivary glands might form secondary to sialadenitis, but not via a luminal organic nidus.

Topics: Adolescent; Adult; Calcium; Calcium Oxalate; Calcium Phosphates; Chlorides; Durapatite; Electron Probe Microanalysis; Female; Humans; Iron; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Microscopy, Electron, Scanning; Middle Aged; Phosphates; Phosphorus; Potassium; Salivary Duct Calculi; Salivary Gland Calculi; Silicones; Sodium; Struvite; Submandibular Gland Diseases; X-Ray Diffraction; Young Adult

Topics: Crystallization; Diagnosis, Differential; Humans; Kidney Calculi; Magnesium Compounds; Male; Middle Aged; Phosphates; Struvite; Tomography, X-Ray Computed; Ureteroscopy; Urinary Tract Infections

Kidney stones are heterogeneous but often grouped together. The potential effects of patient demographics and calendar month (season) on stone composition are not widely appreciated.. The first stone submitted by patients for analysis to the Mayo Clinic Metals Laboratory during 2010 was studied (n=43,545). Stones were classified in the following order: any struvite, any cystine, any uric acid, any brushite, majority (≥50%) calcium oxalate, or majority (≥50%) hydroxyapatite.. Calcium oxalate (67%) was the most common followed by hydroxyapatite (16%), uric acid (8%), struvite (3%), brushite (0.9%), and cystine (0.35%). Men accounted for more stone submissions (58%) than women. However, women submitted more stones than men between the ages of 10-19 (63%) and 20-29 (62%) years. Women submitted the majority of hydroxyapatite (65%) and struvite (65%) stones, whereas men submitted the majority of calcium oxalate (64%) and uric acid (72%) stones (P<0.001). Although calcium oxalate stones were the most common type of stone overall, hydroxyapatite stones were the second most common before age 55 years, whereas uric acid stones were the second most common after age 55 years. More calcium oxalate and uric acid stones were submitted in the summer months (July and August; P<0.001), whereas the season did not influence other stone types.. It is well known that calcium oxalate stones are the most common stone type. However, age and sex have a marked influence on the type of stone formed. The higher number of stones submitted by women compared with men between the ages of 10 and 29 years old and the change in composition among the elderly favoring uric acid have not been widely appreciated. These data also suggest increases in stone risk during the summer, although this is restricted to calcium oxalate and uric acid stones.

Topics: Adolescent; Adult; Age Factors; Aged; Aged, 80 and over; Calcium Oxalate; Calcium Phosphates; Child; Child, Preschool; Cystine; Durapatite; Female; Humans; Infant; Infant, Newborn; Kidney Calculi; Magnesium Compounds; Male; Middle Aged; Phosphates; Seasons; Sex Factors; Struvite; United States; Uric Acid; Young Adult

Results of the structural analysis of urinary sediments by means of infrared spectral microscopy are presented. The results are in good agreement with the results of standard optical microscopy in the case of single-component and crystalline urinary sediments. It is found that for noncrystalline or multicomponent sediments, the suggested spectroscopic method is superior to optical microscopy. The chemical structure of sediments of any molecular origin can be elucidated by this spectroscopic method. The method is sensitive enough to identify solid particles of drugs present in urine. Sulfamethoxazole and traces of other medicines are revealed in this study among the other sediments. We also show that a rather good correlation exists between the type of urinary sediments and the renal stones removed from the same patient. Spectroscopic studies of urinary stones and corresponding sediments from 76 patients suffering from renal stone disease reveal that in 73% of cases such correlation exists. This finding is a strong argument for the use of infrared spectral microscopy to prevent kidney stone disease because stones can be found in an early stage of formation by using the nonintrusive spectroscopic investigation of urinary sediments. Some medical recommendations concerning the overdosing of certain pharmaceuticals can also be derived from the spectroscopic studies of urinary sediments.

Topics: Calcium Oxalate; Calcium Phosphates; Durapatite; Humans; Kidney Calculi; Magnesium Compounds; Microscopy; Optical Phenomena; Phosphates; Spectroscopy, Fourier Transform Infrared; Struvite; Uric Acid; Urinary Calculi

This study was conducted to determine the composition of staghorn stones and to assess the proportion of infected stones as well as the correlation between infection in the stones and bacteria grown in urine. Samples of 45 consecutive stones removed through anatrophic nephrolithotomic procedures were taken from the operation site and samples of urine were obtained by simultaneous bladder catheterization. The frequency of infection in the stones and correlation between infection of stone and urine samples were determined with respect to the composition of the stones. Twenty-two males and 23 females, with respective mean ages of 48.3 ± 15.6 years and 51 ± 7.4 years, were studied. The stone and urine cultures yielded positive results in ten and 16 patients, respectively, of a total of 45 patients (22.2% and 35.5%, respectively). Calcium oxalate was the main constituent of staghorn stones, seen in 31 patients (68.8%), uric acid in 12 patients (26.6%) and struvite and/or calcium phosphate in 11 patients (24.4%). In seven of ten stones with bacterial growth, bacteria were isolated from urine cultures as well, which accounted for a concordance rate of 70%. The bacteria grown in the stone were the cause of urinary tract infection (UTI) in 43.5% of the cases. Stone infection was significantly associated with UTI (OR = 6.47; 95% CI 1.43-31.7, P = 0.021) and presence of phosphate in the stones (OR = 18, 95% CI 3.28-99.6, P = 0.0006). E. coli was the most common bacteria grown from the stones, and was isolated in 50% of the cases; Ureaplasma urealyticum was the most common organism causing UTI, grown in 62.5% of the urine samples. There was a high concordance rate between bacteria in the stones and urine. These findings indicate that the urine culture can provide information for selection of an appropriate anti-microbial agent for stone sterilization. In addition, preventing re-growth or recurrence of stones and treatment of post-surgical infections would be facilitated based on the results of the urine culture.

Topics: Adult; Aged; Anti-Bacterial Agents; Calcium Oxalate; Calcium Phosphates; Female; Humans; Iran; Kidney Calculi; Magnesium Compounds; Male; Middle Aged; Nephrostomy, Percutaneous; Odds Ratio; Phosphates; Prevalence; Risk Factors; Struvite; Treatment Outcome; Uric Acid; Urinary Catheterization; Urinary Tract Infections; Urine

The presence of infectious microorganisms in urinary stones is commonly inferred from stone composition, especially by the presence of struvite in a stone. The presence of highly carbonated apatite has also been proposed as a marker of the presence of bacteria within a stone. We retrospectively studied 368 patients who had undergone percutaneous nephrolithotomy (PCNL), and who also had culture results for both stone and urine. Urine culture showed no association with stone mineral content, but stone culture was more often positive in struvite-containing stones (73 % positive) and majority apatite stones (65 %) than in other stone types (54 %, lower than the others, P < 0.02). In 51 patients in whom the carbonate content of apatite could be measured, carbonate in the apatite was weakly predictive of positive stone culture with an optimal cutoff value of 13.5 % carbonate (sensitivity 0.61, specificity 0.80). In positive cultures of stones (all mineral types combined), organisms that characteristically produce urease were present in 71 % of the cases, with no difference in this proportion among different types of stone. In summary, the type of mineral in the stone was predictive of positive stone culture, but this correlation is imperfect, as over half of non-struvite, non-apatite stones were found to harbor culturable organisms. We conclude that mineral type is an inadequate predictor of whether a stone contains infectious organisms, and that stone culture is more likely to provide information useful to the management of patients undergoing PCNL.

Topics: Apatites; Humans; Kidney Calculi; Magnesium Compounds; Nephrostomy, Percutaneous; Phosphates; Retrospective Studies; Struvite; Urinary Tract Infections

Topics: Acid-Base Equilibrium; Adult; Calcium Oxalate; Calcium Phosphates; Cystinuria; Diagnosis, Differential; Feeding Behavior; Guideline Adherence; Humans; Hyperuricemia; Kidney Calculi; Magnesium Compounds; Male; Phosphates; Prescription Drugs; Recurrence; Risk Factors; Struvite; Urinary Tract Infections; Water-Electrolyte Balance

To evaluate the compositions of the kidney stones obtained from different regions of Turkey and to present the gender and regional differences.. The study included 6453 kidney stones obtained from patients from different parts of Turkey. All of the stones were obtained using ureterorenoscopy, percutaneous stone surgery, laparoscopic or open stone surgery, or extracorporeal shock wave lithotripsy. X-ray diffraction crystallography method was used for analysis.. At the end of the analysis, 11 different stone types including calcium oxalate (Ca-ox) monohydrate (whewellite, COM), Ca-ox dihydrate (weddellite, COD), uric acid, cystine, struvite, biurea, xanthine brushite, quartz, whitlockite, and dahlite were determined either in pure or mixed conditions. Of the stones, 80.4% were Ca-ox (55.7% COM, 5.9% COD, 18.8% COM + COD), 4.8% uric acid, 3.1% cystine, and 3.3% were phosphate stones (dahlite, brushite, struvite, whitlockite). The remaining 8.4% of the stones were in mixed form with different combinations. Of the patients, 4411 were men (68.3%) and 2042 were women (31.7%).. Ca-ox was the most frequently encountered stone type in our country as it is worldwide. The distribution of the other stone types is different than the other countries. The information about the structure of the stone has significant contribution to the understanding of the stone formation etiology, programming of the treatment process, and prevention of the recurrences. The study is significant in presenting the stone profile of Turkey.

Topics: Apatites; Biureas; Calcium Oxalate; Calcium Phosphates; Crystallography, X-Ray; Cystine; Female; Humans; Kidney Calculi; Magnesium Compounds; Male; Phosphates; Quartz; Sex Factors; Struvite; Turkey; Uric Acid; Xanthine

The aim of this study is to identify surgical, patient- and stone-related factors predictive of clinical success and complications after percutaneous nephrolithotomy (PCNL).. We prospectively studied 100 consecutive PCNL procedures. Univariate and multiple regression models were used in order to identify which variables could act as independent predictors of PCNL outcomes. Success was defined as complete absence of fragments in a non-contrast CT. The Clavien-modified grading system was used to classify the complications.. Univariate analysis showed that patients rendered stone-free had a significantly lower stone burden, shorter operating times, single stones and non-struvite composed calculi. Patient age, nephrostomy tract dilation with high pressure balloon and a stone composition different to struvite behaved as significant protective factors for complications. Logistic regression models revealed that the main independent prognostic factor for success was stone surface (OR = 0.997 per mm2, p = 0.000), followed by multiple stones (OR = 0.203, p = 0.050). On the other hand, struvite composition (OR = 5.911, p = 0.028) was an independent predictor for the development of complications, whilst age (OR = 0.936, p = 0.012) and high pressure balloon dilation (OR = 0.041, p = 0.007) were rendered independent protective variables.. Stone burden and multiple calculi in the kidney affect the immediate stone-free rate, whilst Amplatz dilation, struvite stones and young patients lead to a higher incidence of postoperative complications. This information can be very useful for patient counseling, regarding percutaneous kidney stone management.

Topics: Adult; Aged; Aged, 80 and over; Catheterization; Female; Humans; Kidney Calculi; Magnesium Compounds; Male; Middle Aged; Nephrostomy, Percutaneous; Phosphates; Prospective Studies; Risk Factors; Struvite; Treatment Outcome

The purpose of our study was to determine, in vivo, whether single-energy noncontrast computed tomography (NCCT) can accurately predict the presence/percentage of struvite stone composition.. We retrospectively searched for all patients with struvite components on stone composition analysis between January 2008 and March 2012. Inclusion criteria were NCCT prior to stone analysis and stone size ≥4 mm. A single urologist, blinded to stone composition, reviewed all NCCT to acquire stone location, dimensions, and Hounsfield unit (HU). HU density (HUD) was calculated by dividing mean HU by the stone's largest transverse diameter. Stone analysis was performed via Fourier transform infrared spectrometry. Independent sample Student's t-test and analysis of variance (ANOVA) were used to compare HU/HUD among groups. Spearman's correlation test was used to determine the correlation between HU and stone size and also HU/HUD to % of each component within the stone. Significance was considered if p<0.05.. Fourty-four patients met the inclusion criteria. Struvite was the most prevalent component with mean percentage of 50.1%±17.7%. Mean HU and HUD were 820.2±357.9 and 67.5±54.9, respectively. Struvite component analysis revealed a nonsignificant positive correlation with HU (R=0.017; p=0.912) and negative with HUD (R=-0.20; p=0.898). Overall, 3 (6.8%) had <20% of struvite component; 11 (25%), 25 (56.8%), and 5 (11.4%) had 21% to 40%, 41% to 60%, and 61% to 80% of struvite, respectively. ANOVA revealed no difference among groups regarding HU (p=0.68) and HUD (p=0.37), with important overlaps. When comparing pure struvite stones (n=5) with other miscellaneous stones (n=39), no difference was found for HU (p=0.09) but HUD was significantly lower for pure stones (27.9±23.6 v 72.5±55.9, respectively; p=0.006). Again, significant overlaps were seen.. Pure struvite stones have significantly lower HUD than mixed struvite stones, but overlap exists. A low HUD may increase the suspicion for a pure struvite calculus.

Topics: Contrast Media; Humans; Kidney Calculi; Magnesium Compounds; Phosphates; Struvite; Tomography, X-Ray Computed

Urinary calculi are formed from a result of biological mal-adjustment of urine leading to deposits of salt and mineral crystals along the urinary collecting system. They are usually multiphasic material with complex compositions. The objective of this study is to identify and characterize a series of urinary calculi samples using a combination of thermogravimetric analysis (TGA) with electron dispersive spectroscopy (EDS). These samples were retrieved during percutaneous nephrolithotripsy. Additional characterization by hardness value and microstructure is also carried out for co-relation study. The samples are found to be uric acid, calcium oxalates and magnesium ammonium phosphate hexahydrate. TGA is indeed one of the viable analytical tools for urinary calculi as it is fast and simple. The combinational application of EDS is beneficial when there is a need for differentiated qualitative chemical composition detection at the identified nuclei position for urinary calculi with spatial variation in composition. The combination of TGA and EDS will thus facilitate the correct diagnosis and treatment by clinicians.

Topics: Calcium Oxalate; Hardness; Humans; Kidney Calculi; Magnesium Compounds; Phosphates; Spectrum Analysis; Struvite; Thermogravimetry; Uric Acid

Bacterial imprints are always observed on highly carbonated apatite kidney stones but not struvite kidney stones. Struvite and carbonated apatite stones with a high CO(3)(2-)/PO(4)(3-) rate are believed to develop from infections, but their structural differences at the mesoscopic scale lack explanation.. We investigated 17 urinary calculi composed mainly of struvite or carbonated apatite by Fourier transform infrared, scanning electron microscopy, and powder neutron diffraction techniques.. Carbonated apatite but not struvite stones showed bacterial imprints. If the same stone contained both carbonated apatite and struvite components, bacterial imprints were observed on the carbonated apatite but not the struvite part. Moreover, neutron powder diffraction experiments revealed the crystal size of struvite stones were larger than that of carbonated apatite stones (250 ± 50 vs 50 nm).. Bacterial imprints may appear more easily on kidney stones with small nanocrystals, such as carbonated apatite than with large nanocrystals, such as struvite. This approach may help identify bacteria contributing to stone formation, perhaps with negative results of urine culture.

Topics: Adult; Aged; Aged, 80 and over; Apatites; Calcium Carbonate; Child, Preschool; Female; Humans; Kidney Calculi; Magnesium Compounds; Male; Microscopy, Electron, Scanning; Middle Aged; Nanoparticles; Neutron Diffraction; Phosphates; Powder Diffraction; Spectroscopy, Fourier Transform Infrared; Struvite

Studies that evaluate the effect of age and gender on the stone composition are scarce. The aim of this study is to highlight the modification of epidemiological characteristics of this pathology according to patients' sex and age.. We studied 1269 urolithiasic patients ranging from 6 months to 92 years old and known as having urinary stones (752 males and 517 females). Stone analysis was performed respectively using a stereomicroscope and infrared spectroscopy to determine, respectively, the morphological type and molecular composition of each.. The annual average incidence of new stone formation was 30.25 per 100,000 inhabitants. In 1041 patients (81%), calculi were located in the upper urinary tract. Children and old man were more affected by bladder stone. Calcium oxalate monohydrate remains the most frequent stone component even if its frequency fell according to age (63.2% in teenagers and 40.6% in elderly [p<0.05]) in favour of the increase of uric acid stones (3,5% in teenagers and 41.5% in elderly [p<0.05]). Struvite stones were rare (3.5%) and more frequent in children.. The analysis of these data shows that urinary stones in Tunisia are tending to evolve in the same direction as in industrialized countries.

Topics: Adolescent; Adult; Age Distribution; Age of Onset; Aged; Aged, 80 and over; Calcium Oxalate; Child; Child, Preschool; Developing Countries; Female; Humans; Incidence; Infant; Kidney Calculi; Magnesium Compounds; Male; Middle Aged; Phosphates; Retrospective Studies; Sex Distribution; Social Change; Spectrophotometry, Infrared; Struvite; Tunisia; Uric Acid; Young Adult

Studies that evaluate the effect of age on stone composition are scarce. The aim of this study was to highlight the changes in epidemiological characteristics (stone composition and location) of urolithiasis according to patients' age.. We studied 1,301 urolithiasis patients with age ranging from 6 months to 92 yr (781 males and 520 females). Stone analysis was performed using a stereomicroscope and infrared spectroscopy to determine the morphological type and molecular composition of each stone.. The annual average incidence of new stone formation was 31.7 per 100,000 persons. In 71.8% of cases, calculi were located in the upper urinary tract. Compared to other age groups, children and old men were more affected by bladder stones. Calcium oxalate monohydrate was the most frequent stone component, even though its frequency decreased with age (59.5% in young adults and 43.7% in the elderly, P<0.05) in favor of an increase in uric acid stones (11.5% in young adults and 36.4% in the elderly, P<0.05). Struvite stones were rare (3.8%) and more frequent in children than in adults.. The analysis of these data showed that urinary stones in Tunisian patients are tending to evolve in the same direction as the stones in patients from industrialized countries.

Topics: Adolescent; Adult; Age Factors; Aged; Aged, 80 and over; Calcium Oxalate; Child; Child, Preschool; Female; Humans; Infant; Kidney Calculi; Magnesium Compounds; Male; Middle Aged; Phosphates; Retrospective Studies; Spectrophotometry, Infrared; Struvite; Tunisia; Uric Acid; Urinary Bladder Calculi; Urinary Calculi; Young Adult

To characterize the magnetic resonance (MR) relaxation times (ie, T1 and T2 relaxation times) of a variety of kidney stone specimens using an ultra-short echo time (UTE) sequence and to correlate these values to their size and composition based on chemical analysis.. This was an institutional review board-approved, Health Insurance Portability and Accountability Act-compliant study with waiver of informed consent. Between April 2009 and September 2009, stones from 36 patients underwent 1.5T MR imaging with two UTE pulse sequences to measure: 1) T2 relaxation times (repetition time [TR] = 1 second and multiple echo times [TEs] ranging from 0.1 ms up to 2 ms); 2) T1 relaxation times (TE = 0.1 ms and multiple TRs ranging from 500 ms to 2.5 seconds). A tube containing a solution of water and hydroxyapatite crystals near the stones served as reference standard. Results were compared to previous data obtained from experiments measuring the T1 and T2 of pure calcium oxalate and hydroxyapatite crystals suspended in water. Stones were submitted for chemical analysis. The stone size and composition was correlated to the relaxation time, and signal intensity.. The average stone size was 0.86 cm (range 0.1-3.3 cm). Twenty-one stones were visible by MR. The average size of MR-visible stones was 1.1 cm (range 0.15-3.3 cm) compared to 0.46 cm (range 0.1-0.9) for nonvisible stones. The mean T1 and T2 of MR-visible stones were 950 ms (range 138-3000 ms) and 3.12 ms (range 0.27-12 ms), respectively. The T1 (mean 1143, range 740-1583) and T1 (mean 8.31, range 4.6-12) values of calcium phosphate were longer than that for other stone compositions T1 (mean 953, range 138-3000) and T2 (mean 2.58, range 0.27-5.8; P < .05).. The T1- and T2-relaxation times of kidney stones are variable and depend on their composition and the size of the stones. UTE MR allows for visualization of renal stones in vitro.

Topics: Calcium Oxalate; Calcium Phosphates; Durapatite; Humans; In Vitro Techniques; Kidney Calculi; Magnesium Compounds; Magnetic Resonance Imaging; Phosphates; Struvite; Uric Acid

The purpose of this study was to determine the ex vivo ability of dual-energy dual-source CT (DSCT) with additional tin filtration to differentiate among five groups of human renal stone types.. Forty-three renal stones of 10 types were categorized into five primary groups on the basis of effective atomic numbers, which were calculated as the weighted average of the atomic numbers of constituent atoms. Stones were embedded in porcine kidneys and placed in a 35-cm water phantom. Dual-energy DSCT scans were performed at 80 and 140 kV with and without tin filtration of the 140-kV beam. The CT number ratio, defined as the ratio of the CT number of a given material in the low-energy image to the CT number of the same material in the high-energy image, was calculated on a volumetric voxel-by-voxel basis for each stone. Statistical analysis was performed, and receiver operating characteristic (ROC) curves were plotted to compare the difference in CT number ratio with and without tin filtration, and to measure the discrimination among stone groups.. The CT number ratio of non-uric acid stones increased on average by 0.17 (range, 0.03-0.36) with tin filtration. The CT number ratios for non-uric acid stone groups were not significantly different (p > 0.05) between any of the two adjacent groups without tin filtration. Use of the additional tin filtration on the high-energy x-ray tube significantly improved the separation of non-uric acid stone types by CT number ratio (p < 0.05). The area under the ROC curve increased from 0.78 to 0.84 without fin filtration and to 0.89-0.95 with tin filtration.. Our results showed better separation among different stone types when additional tin filtration was used on dual-energy DSCT. The increased spectral separation allowed a five-group stone classification scheme. Some overlapping between particular stone types still exists, including brushite and calcium oxalate.

Topics: Animals; Apatites; Calcium Oxalate; Calcium Phosphates; Cystine; Diagnosis, Differential; Durapatite; Humans; In Vitro Techniques; Kidney Calculi; Magnesium Compounds; Phantoms, Imaging; Phosphates; Radiographic Image Interpretation, Computer-Assisted; Retrospective Studies; ROC Curve; Sensitivity and Specificity; Struvite; Swine; Tomography, X-Ray Computed; Uric Acid

To evaluate the factors that affect the enzymatic dissolution rate of calcium oxalate monohydrate (COM), calcium phosphate (brushite), and magnesium ammonium phosphate (struvite) crystals as enzymatic digestion of kidney stones could enhance lithotripsy or provide alternatives to surgical removal.. At pH 4.2, pelleted COM crystals were combined with oxalate decarboxylase (ODC from Bacillus subtilis), oxalate oxidase (from Hordeum vulgare), or control. Crystal dissolution was followed by measuring increases in solution calcium ion concentration. For phosphate-based crystals, the rates of phosphorolysis by the enzyme purine nucleoside phosphorylase (PNP, assay form) were compared to the control solution using spectrophotometry.. The addition of ODC to COM crystals resulted in production of highly soluble calcium formate and a 15-fold increase in COM solubility. By adding a formate-catabolizing enzyme (formate dehydrogenase), dissolution increased 47-fold compared with controls with nearly one half of the mineral dissolved. Oxalate oxidase showed much lower activity than ODC in COM dissolution. Using inorganic phosphate as a substrate, PNP was able to dissolve both brushite and struvite minerals in water at concentrations near saturation. Measuring dissolution by adding more PNP was not possible because of equilibrium and assay detection restraints.. Stone dissolution using enzymes appears to be viable, particularly for oxalate-based minerals. In a closed system, product inhibition by calcium formate appeared to limit the extent of COM crystal dissolution using ODC. Although phosphate-containing minerals appear to be suitable phosphate sources for PNP, the reversibility of the reaction limits the use of this enzyme.

Topics: Calcium Oxalate; Calcium Phosphates; Carboxy-Lyases; Humans; In Vitro Techniques; Kidney Calculi; Magnesium Compounds; Oxidoreductases; Phosphates; Purine-Nucleoside Phosphorylase; Solubility; Struvite

Kidney stones are a potential risk factor for chronic kidney disease. The impact of different urinary stone components on renal function is unknown. In this study, we retrospectively reviewed 1,918 medical records of patients with urolithiasis. The renal function was evaluated as estimated glomerular filtration rate. All the stones were analyzed by Fourier transform infrared spectroscopy. The patients were divided into five groups according to the stone components. Statistical analysis was performed with analysis of variance. All the patients with stones had Stage 2-3 chronic kidney disease. The patients with uric acid and struvite stones had significantly lower estimated glomerular filtration rate compared with those having other stone components (p<0.01). Furthermore, the patients with calcium-containing stones (calcium oxalate and calcium phosphate) had significantly better renal function than those with non-calcium-containing stones (struvite and uric acid, p<0.01). Patients with urolithiasis had decreased renal function, and the impact of renal function varied depending on the stone components. We conclude that stone analysis is important in predicting the change in renal function in patients with urolithiasis. Moreover, the patients with non-calcium-containing stones, such as struvite and uric acid stones, should be carefully evaluated and treated to preserve their renal function.

Topics: Adult; Aged; Calcium Oxalate; Calcium Phosphates; Female; Glomerular Filtration Rate; Humans; Kidney Calculi; Magnesium Compounds; Male; Middle Aged; Phosphates; Retrospective Studies; Spectroscopy, Fourier Transform Infrared; Struvite; Uric Acid; Urolithiasis

Using thermoluminescence spectrometer, X-ray diffraction and Fourier transform infrared spectroscopy, the chemical compositions of four types of kidney stones were investigated. They are calcium oxalate, uric acid, calcium phosphate and magnesium ammonium phosphate calculi (struvite). Experimental results showed that in the 305 cases of stones, calculi oxalate stones were found to account for 63%, uric acid stones 22%, calcium phosphate stones 8%, struvite 5%, and the stones with other compositions 2%. There were significant differences in the thermoluminescence spectra among the 4 types of urinary stones, which can provide an important basis for the clinic diagnosis of urinary stone types.

Topics: Calcium Oxalate; Calcium Phosphates; Humans; Kidney Calculi; Magnesium Compounds; Phosphates; Spectroscopy, Fourier Transform Infrared; Struvite; Uric Acid; Urinary Calculi; X-Ray Diffraction

The epidemiology of renal stones has changed all over the world toward a predominance of calcium oxalate stones. However, studies evaluating the influence of age and gender on the distribution of the various types of urinary calculi are scarce. We will present the results of a study based on 205 calculi (from 122 boys and 83 girls) analyzed by infrared spectroscopy between 1993 and 2007. 90% of stones were collected by surgery, whereas only 6% by spontaneous passage. The biological exploration was performed in only 126 cases. Etiology was metabolic in 13.5%. 10.7% of stones were infectious, 13.1% were endemic and 54.9% were idiopathic. 7.8% were secondary to urinary stasis with malformation but no infection. Calcium oxalate (CaOx) was the predominant constituent in 54.7% of stones, followed by calcium phosphate and purines 14.6% in each of the cases. We found an increasing prevalence of calcium oxalate stones with age in both genders (42.9% in infant vs. 59.3% in child) (P < 0.05). Struvite stones were more frequent in infant than children. Purine stones were predominant in 20% of cases, but its prevalence decreases with age. The increase in calcium oxalate stone in school age children and the decrease in struvite and purine stones confirm the change on the etiology of urolithiasis according to age.

Topics: Adolescent; Age Factors; Calcium Oxalate; Child; Child, Preschool; Female; Humans; Kidney Calculi; Magnesium Compounds; Male; Phosphates; Purines; Spectrophotometry, Infrared; Struvite; Tunisia

The objective of this study was to determine the composition of kidney stone fragments obtained after extracorporeal shock wave lithotripsy (ESWL).. Kidney stone fragments from 25 patients with urolithiasis treated with ESWL were submitted for morphological analysis. The composition was determined for all the recovered fragments.. Thirteen patients (52%) had pure stones. The most common type of pure stone was calcium oxalate (61.6%), of which half was the monohydrate type (COM) and half was the dihydrate type (COD). The other pure stones consisted of either uric acid (30.8%) or struvite (7.6%). For mixed stones, the most frequently observed component was COM or COD (50%), followed by a mixture of COD and carbapatite (25.1%).. Our findings indicate that the composition of kidney stone fragments recovered after ESWL can be determined. Knowledge of stone composition is fundamental to understand the etiology of lithogenesis.

Topics: Adult; Aged; Calcium Oxalate; Female; Humans; Kidney Calculi; Lithotripsy; Magnesium Compounds; Male; Middle Aged; Phosphates; Struvite; Uric Acid

To get complete information about the chemical composition and physicochemical principles underlying the formation of stone there is a need for more precise information. At present there is no single analytical procedure that provides an exact quantitative analysis of urinary calculi. In this present procedure it is assumed that only calcium oxalate monohydrate, hydroxyapatite, or magnesium ammonium phosphate hexahydrate are present in stone, therefore the percent chemical composition of stone is calculated on the basis of molecular weight of an element and related molecular formula of the stone. By analysis of 100 stones the chemical composition observed with Mean +/- SD value for calcium is 25.68 +/- 5.38, for Calcium oxalate hydrate crystal is 32.84 +/- 17.28 which contains oxalic acid 20.35 +/- 10.70, for Apatite crystal is found to be 41.70 +/- 16.56 which contains inorganic phosphate 8.09 +/- 3.08. Total uric acid found in these stones is 27.12 +/- 11.42. Major component are calcium oxalate 32.8% (combined monohydrate and dihydrate), Phosphate 41.7%, Magnesium ammonium phosphate hexahydrate 3.3% and uric acid 27.1%. No pure stone was obtained. Calcium oxalate was present in nearly all stones, and the majority of renal calcium stones contains mixtures of calcium oxalate and calcium phosphates in addition some contains uric acid or magnesium ammonium phosphate. The mixture of calcium oxalate/uric acid/magnesium ammonium phosphate hexa hydrate has never been observed.

Topics: Calcium; Calcium Oxalate; Humans; Kidney Calculi; Magnesium Compounds; Oxalic Acid; Phosphates; Struvite; Uric Acid; Urinary Calculi

Struvite is one of the components of urinary stone. Large number of people is suffering from urinary stones (calculi) problem all over the globe. These stones can grow rapidly forming "staghorn-calculi", which is more painful urological disorder. Therefore, it is of prime importance to study the growth and inhibition of Struvite crystals. This in vitro study has been carried out in the presence of herbal extract of Commiphora wightii by using single diffusion gel growth technique. Sodium metasilicate solution of specific gravity 1.05 and an aqueous solution of ammonium dihydrogen phosphate of 0.5 M concentration were mixed so that the pH value 7.0 could be set. After the gelation, equal amount of supernatant solutions comprising of pure 1.0 M magnesium acetate as well as the mixtures of magnesium acetate and the herbal extract solutions of 0.5 and 1% concentrations of C. wightii were gently poured on the set gels. From the study of growth and inhibition behavior of Struvite crystals, it was found that C. wightii inhibits the growth of the Struvite. This study incorporates multidisciplinary interests and may be used for formulating the strategy for prevention or dissolution of urinary stones.

Topics: Chemical Precipitation; Commiphora; Crystallization; Dose-Response Relationship, Drug; Down-Regulation; In Vitro Techniques; Kidney Calculi; Magnesium Compounds; Particle Size; Phosphates; Plant Extracts; Solubility; Struvite; Urinary Calculi

To analyse three outcomes of stone prevention strategies in one clinic devoted to that activity since 1969, i.e. stone recurrence rates, stone-related procedures and 24-h urinary stone risk factor, to assess whether such treatment can be maintained over long periods.. We selected 2509 patients with at least one laboratory follow-up after initial clinical and laboratory evaluation. We divided them into five time cohorts of 5, 10, 15, 20 and >20 years of follow-up. Rates of new stones and stone-related procedures, and 24-h urinary stone risk factors were compared between the cohorts using analysis of variance and general linear modelling.. Stone rates and rates of stone-related procedures declined in all five cohorts, as did 24-h urinary stone risk indices. We found no diminution of treatment effects for any of these three over time.. Those patients who remained under active care had significant reductions in stone recurrence and rates of stone-related urological procedures for up to >20 years. However, only a small fraction of patients who entered the clinic remained for such long periods. Urine testing substantiates impressive and sustained reductions in supersaturation, the principle driving force for stone formation. Overall, for those patients willing to remain in continuous treatment for periods of up to three decades, medical stone prevention appears to be effective in maintaining low recurrence and procedure rates.

Topics: Adult; Calcium Oxalate; Calcium Phosphates; Cystine; Epidemiologic Methods; Female; Humans; Kidney Calculi; Magnesium Compounds; Male; Middle Aged; Phosphates; Risk Factors; Secondary Prevention; Struvite; Time Factors; Uric Acid; Urinary Calculi

Crossed fused renal ectopia is a rare renal anomaly. Formation of staghorn and struvite calculi within it has never been reported in local literature. A 25-year-old man with macrohematuria and right flank pain was admitted to the hospital. An intravenous pyelography revealed right sided crossed fused ectopic kidney showing a staghorn and struvite calculi in upper-moiety along with gross hydronephrosis. Patient was conservatively managed after exclusion of other congenital anomalies.

Topics: Adult; Diagnosis, Differential; Humans; Hydronephrosis; Kidney; Kidney Calculi; Magnesium Compounds; Male; Phosphates; Radiography; Struvite

Some patients undergoing percutaneous nephrolithotomy (PCNL) have purulent fluid in the pelvicaliceal system at the time of puncture, although preoperative features are not suggestive of infection. We report the management and outcome of 19 such patients.. Among the 639 patients who underwent PCNL at our center from July 2000 to October 2003, 19 had purulent fluid in the kidney at initial puncture. The preoperative findings, operative details, hospital course, and final outcome in these patients were analyzed. Twelve patients had stone removal at the first sitting (option 1), while seven had a nephrostomy tube placed initially with stone removal deferred for 3 to 7 days (option 2).. With option 1, stones were cleared with one to three tracts in 45 to 120 minutes. Seven patients recovered smoothly, three had transient fever, while one had grade I and another had grade II sepsis. The purulent fluid grew E. coli in two cases and Proteus or Serratia in one case each and was sterile in eight. With option 2, stones were cleared using one to three tracts in 60 to 100 minutes. The fluid grew E. coli or Klebsiella in one case each and was sterile in five. Three patients had a smooth recovery, two had transient fever, one had grade I sepsis, and another had grade II sepsis. Risk factors for sepsis, irrespective of the option, were a recent history of febrile urinary-tract infection, borderline elevation of total leukocyte count, thick or foul pus as opposed to mere turbidity, the use of a single tube or tract or delayed creation of second tracts, and operating time >90 minutes.. Despite normal preoperative urine and blood values, one may find purulence on puncture during PCNL, which is not always infected. If any one or more of the above risk factors is present, it is safer to drain the kidney initially, making sure that all blocked calices are drained, inserting multiple tubes if necessary.

Topics: Adult; Calcium Oxalate; Female; Fever; Gram-Negative Bacteria; Gram-Negative Bacterial Infections; Humans; Kidney Calculi; Kidney Calices; Kidney Pelvis; Magnesium Compounds; Male; Middle Aged; Nephrostomy, Percutaneous; Phosphates; Risk Factors; Sepsis; Struvite; Suppuration; Treatment Outcome

In this article a theoretical framework is developed for the mechanics of kidney stones with an isotropic, random microstructure--such as those comprised of cystine or struvite. The approach is based on a micromechanical description of kidney stones comprised of crystals in a binding matrix. Stress concentration functions are developed to determine load sharing of the particle phase and the binding matrix phase. Measurements have shown the inclusions to be considerably harder than the binder; consequently, loading of a stone leads to higher stresses in the inclusions than in the binder. As an illustration of the theory, the fatigue of kidney stones subject to shock-wave lithotripsy is considered. Stress concentration functions are used to construct fatigue-life estimates for each phase, as a function of the volume fraction and of the mechanical properties of the constituents, as well as the loading from SWL. The failure of the binding matrix, or of the particulate phase, is determined explicitly in a model for the accumulation of distributed damage. The theory can be used to assess the importance of microscale heterogeneity on the comminution of renal calculi, and to estimate the number of cycles to failure in terms of measurable material properties.

Topics: Biomechanical Phenomena; Computer Simulation; Cystine; Elasticity; Kidney Calculi; Lithotripsy; Magnesium Compounds; Models, Biological; Particle Size; Phosphates; Stress, Mechanical; Struvite; Uric Acid

To evaluate the safety and efficacy of percutaneous nephrolithotomy (PCNL) for the management of complete staghorn calculi in children

Topics: Calcium; Calcium Oxalate; Child, Preschool; Citric Acid; Female; Humans; Infant; Kidney Calculi; Lithotripsy; Magnesium Compounds; Male; Nephrostomy, Percutaneous; Phosphates; Recurrence; Struvite; Uric Acid

To elucidate the factors contributing to staghorn stone formation in patients.. The records of 82 patients (44 men and 38 women) with complete staghorn calculi were reviewed retrospectively for clinical presentation, metabolic disturbances and anatomical abnormalities.. There were 79 unilateral and three bilateral cases. The patient performance of the activities of daily life was assessed with the modified Rankin scale (MRS) and it was found that 69 patients were functionally independent (84.1%, MRS 0-1) and 10 patients had a severe disability (12.2%, MRS 4-5). Seven patients had chronic indwelling catheters (8.5%). A positive urine culture was found in 24.4% of patients. Analysis of stone composition revealed magnesium ammonium phosphate and mixed calcium oxalate-phosphate were the most frequently identified types of stone (32.1% and 22.2%, respectively). Urinary pH was low in patients with uric acid stones (mean 5.4). Hyperuricemia, cystinuria and hypercalciuria were found in 14.6%, 2.4% and 37.8%, respectively. Hypercalciuria was found more frequently in calcium-stone cases. Eleven patients (13.4%) showed structural abnormalities of the kidney.. Our data show that the patients with severe disability, urinary tract infection and hypercalciuria could be recognized more frequently in staghorn calculi compared with common urolithiasis. However, in Western countries, the frequency of both urinary tract infection and struvite stones is much higher than in our data. Other Japanese authors have also reported the low frequency of struvite stones in staghorn calculi, suggesting that various factors other than urinary tract infection possibly contribute to the formation of staghorn calculi in Japan.

Topics: Activities of Daily Living; Adult; Aged; Calcium; Calcium Oxalate; Calcium Phosphates; Catheters, Indwelling; Cystinuria; Female; Humans; Hydrogen-Ion Concentration; Hyperuricemia; Kidney; Kidney Calculi; Magnesium Compounds; Male; Middle Aged; Phosphates; Retrospective Studies; Struvite; Uric Acid; Urinary Tract Infections; Urine

To determine the chemical composition of pure and mixed urinary calculi by multislice helical computed tomography (CT) in an in vitro setting. CT is becoming the preferred radiologic examination in diagnosis and management of calculus disease. The management of calculus disease can be facilitated by ascertaining the stone composition. Unnecessary shock wave treatment could be avoided if the fragility of the stones could be predicted at diagnosis.. A total of 107 stones (86 pure and 21 mixed) were measured in a multislice helical scanner within an air-filled environment. The scans were performed at two energy levels, 80 kV and 120 kV, with a 1-mm slice thickness. The chemical compositions of the urinary stones were assessed on the basis of the differences in the densities measured in Hounsfield units. The stones were assigned to six different groups according to the density measured in Hounsfield units: uric acid, struvite, cystine, calcium phosphate, calcium oxalate monohydrate, and calcium oxalate dihydrate.. The differences in the density measured by multislice helical CT at 120 kV for the six groups of pure stones were statistically significant. The densities of the different regions within the mixed stones were also significantly different statistically from each other. The densities of the different regions measured in the mixed stones were not different from the densities of the corresponding pure stones. This finding supports the idea that different chemical compositions within a stone can be identified by their densities measured by multislice helical CT.. The chemical compositions of both pure and mixed stones can be determined by multislice helical CT in an in vitro setting. The feasibility of in vivo determinations remains to be clarified.

Topics: Calcium Oxalate; Calcium Phosphates; Cystine; Humans; In Vitro Techniques; Kidney Calculi; Magnesium Compounds; Phosphates; Struvite; Tomography, Spiral Computed; Uric Acid

Topics: Anti-Bacterial Agents; Catheterization; Child; Endotoxemia; Endotoxins; Humans; Kidney Calculi; Magnesium Compounds; Male; Nephrostomy, Percutaneous; Phosphates; Postoperative Complications; Premedication; Struvite; Urinary Catheterization

Comprehensive metabolic evaluation has become an important aspect of the management of recurrent nephrolithiasis, yet the role of stone analysis is often neglected or perhaps underestimated. The purpose of this study was to determine the role of stone analysis in medical decision making in patients with recurrent nephrolithiasis.. We evaluated 100 consecutive stone-forming patients who had undergone compositional stone analysis as well as comprehensive metabolic evaluation at our institution. An analysis of stone composition in relation to metabolic disturbances was performed. Patients were stratified into two groups: calcium and non-calcium stone formers.. Patients having non-calcium stones were found to have a metabolic analysis reflecting specific metabolic disorders. Alternatively, patients with calcium stones were heterogeneous with regard to metabolic disorders, but there was a significant likelihood of renal tubular acidosis in those patients with calcium phosphate calculi. On the basis of these results, a simplified metabolic evaluation and nonselective medical therapy based on stone composition was formulated to facilitate assessment, management, and monitoring of stone disease.. Compositional stone analysis should be an integral part of the metabolic evaluation of patients with nephrolithiasis. Moreover, stone analysis alone may provide guidance for therapeutic treatment and obviate a formal metabolic evaluation.

Topics: Acidosis, Renal Tubular; Calcium; Calcium Phosphates; Cystine; Female; Humans; Kidney Calculi; Magnesium Compounds; Male; Metabolic Diseases; Phosphates; Struvite; Uric Acid

Urinalysis was performed on 41 cats with no history of urinary tract disease. Samples were divided into aliquots, stored under differing condition and then examined for the presence of crystalluria. Crystalluria was detected in at least one stored sample in 92% of cats fed a mixed wet/dry food diet compared to 24% in the fresh sample. Crystalluria was not detected in any sample or aliquot from cats fed all wet food diets.

Topics: Animal Feed; Animals; Cat Diseases; Cats; Female; Kidney Calculi; Magnesium Compounds; Male; Phosphates; Predictive Value of Tests; Specimen Handling; Struvite

This study reports the first four cases of encrusted pyelitis involving native kidneys. The clinical features, management, and outcome of these patients were analyzed. Predisposing factors were underlying urologic disease and/or urologic manipulations, debilitating diseases, hospitalization, and prolonged antibiotic therapies. Presenting symptoms were renal failure in three patients with ureteroileal urinary diversion and manifestations of cystitis in one patient. Computed tomography scan of the urinary tract was critical for diagnosis. Presence of struvite was demonstrated by crystalluria and infrared spectrophotometry analysis of the encrusted material. Corynebacterium urealyticum urinary infection was identified in one case. Surgery (one patient) and palliative ureteral diversion (one patient), respectively, led to death and end-stage renal failure. Successful dissolution of encrusted pyelitis was obtained in two patients treated with intravenous vancomycin and local acidification of the renal collecting system. Clinical observation shows that encrusted pyelitis is a threatening disorder that destroys the native kidneys and may lead to end-stage renal failure. Successful treatment of the disease by chemolysis and antibiotics depends on correct and early diagnosis. Diagnosis required recognition of the predisposing factors, computed tomography imaging of the urinary tract, crystalluria, and identification of urea-splitting bacteria with prolonged culture on selective medium.

Topics: Aged; Anti-Bacterial Agents; Corynebacterium; Crystallization; Female; Humans; Kidney Calculi; Magnesium Compounds; Male; Middle Aged; Phosphates; Pyelitis; Risk Factors; Struvite; Tomography, X-Ray Computed; Vancomycin

We studied the relationship of stone frequency and composition to age, sex and stone weight.. A retrospective study was performed of all 15,624 stones submitted for analysis with infrared and wet chemical methods in Newfoundland and Labrador from 1979 to 1998.. There were 1,067 bladder stones of which 216 contained magnesium ammonium phosphate. The remaining 14,557 stones were from the kidney and ureter, and 11,707 were composed only of calcium oxalate and/or phosphate. Of the remaining 2,850 kidney and ureter stones magnesium ammonium phosphate was present in 573, uric acid/urate without magnesium ammonium phosphate in 1,109 and other compounds in 1,168. The 11,707 oxalate phosphate group was subdivided by infrared peak analysis based on oxalate-to-phosphate ratio into phosphate-ratio 1 or less, intermediate-1 to 10 and oxalate-10+. Oxalate comprised 65% of the 11,707 stones compared to 16% for phosphate. Women submitted 52% of phosphate stones compared with 28% of oxalate stones. From the first (1980 to 1983) to the last (1995 to 1998) complete 4-year study periods, there was a relative increase in oxalate and decrease in phosphate stones, associated with increasing age from decades 5 to 6 for oxalate and phosphate stones, except that the age peak for phosphate stones in women remained in decade 3. Median weight of 1, 828 phosphate stones was 43 mg. (mean 234) compared with 25 mg. (mean 98) for 7,634 oxalate stones. Male-to-female ratio was 0.91 for phosphate stones compared with 2.62 for oxalate stones.. Phosphate stones were on average heavier and relatively more common in women, had an earlier age peak frequency in women than oxalate stones and became less frequent during our last 4-year study period. In contrast, oxalate stones were much more common, of lighter weight and became more frequent with time.

Topics: Adolescent; Adult; Age Factors; Aged; Child; Female; Humans; Kidney Calculi; Magnesium Compounds; Male; Middle Aged; Oxalates; Phosphates; Retrospective Studies; Sex Factors; Struvite; Ureteral Calculi; Urinary Bladder Calculi; Urinary Calculi

We investigated the applicability of solid-state nuclear magnetic resonance (NMR) spectroscopy to obtain information about the structure and composition of renal calculi.. Various types urinary and bladder stones as well as a variety of presumed constituents were investigated using 13C and 31P magic-angle spinning (MAS) solid-state NMR. Different experimental methods were applied to differentiate resonances from crystalline/amorphous (immobile/mobile) as well as protonated/non-protonated moieties. The NMR spectra were analyzed using multiple-component numerical simulations and iterative fitting to identify and quantify the major amorphous or crystalline organic and inorganic components.. By comparison of the NMR spectra for the various renal calculi with those obtained under similar conditions for various presumed components, it is demonstrated possible to unambiguously distinguish and quantify the major amorphous or crystalline organic and inorganic components. The components are identified in terms of their isotropic and anisotropic chemical shielding parameters, protonation or proximity of protons, and the degree of crystallinity/mobility. For the calculi investigated we have detected and quantified calcium oxalate, uric acid, struvite, and calcium phosphates that closely resemble brushite and calcium hydroxyapatite.. Using 13C and 31P MAS NMR spectroscopy we have been able to account for 60 to 85% (by weight) of the constituents in the calculi investigated. The ability to identify and quantify both crystalline and amorphous components makes solid-state NMR an interesting new method for the compositional analysis of renal calculi.

Topics: Calcium Oxalate; Calcium Phosphates; Carbon Isotopes; Computer Simulation; Crystallography; Durapatite; Electron Spin Resonance Spectroscopy; Humans; Kidney Calculi; Magnesium Compounds; Magnetic Resonance Spectroscopy; Models, Chemical; Phosphates; Phosphorus Isotopes; Struvite; Uric Acid; Urinary Bladder Calculi

A new chemolytic therapy with amino acid preparation was tried for use on struvite renal stones in two dogs, which were admitted to Azabu University Veterinary Teaching Hospital. No other special diet, for the purpose of dissolving the stones, was fed during the treatment. Dissolution of the stones began at week 1, and no stone was detected on radiography at week 4 in both cases. The amino acid preparation thereafter has been administered every 2-3 days to prevent formation of the stones. After 6 months from treatment, complete dissolution was confirmed, and no relapse has been observed. Therefore, it is concluded that chemolytic therapy with amino acid preparation might be useful for the treatment of nephrolithiasis with struvite renal stones in dogs.

Topics: Animals; Dog Diseases; Dogs; Kidney; Kidney Calculi; Magnesium Compounds; Male; Phosphates; Radiography; Struvite

In this paper, the clinical and metabolic patterns of nephrolithiasis in different ages of adulthood are studied.. Eight-hundred patients observed at the Mauriziano Hospital between 1990 and 1995, were classified into 3 groups, on the basis of age at the onset of disease: A: 20 through 39 years; B: 40 through 59; C: 60 years and over.. Calcium-oxalate stones had a lower recurrence in C (19.1%) and B (31.5%) than in A (41.7%). Pure uric acid stones recurred in 18.9% of C, 16.7% of B and 4.3% of A. The prevalence of hypercalciuria was higher in A (50.3%) than in B (35.9%) and C (36%); so did hypocitraturia. Hyperuricuria was lower in A (5%, p < 0.05) than in B (9.4%) and C (10%). Low urine pH (< 5.5) was 13% in A, 21.3% in B, 38% in C. Prevalence of hyperoxaluria was about 14% in all groups. The whole prevalence of secondary forms of stone disease was 13% in A, 12% in B and 30% in C. Differences among groups were mainly due to prevalence of urological abnormalities and urinary tract infection. In patients without metabolic disturbances. urological abnormalities or urinary tract infections altogether, were 4.6% in A; 5.2% in B; 33% in C. Urological approach removed 8% of stones in A, 5.6% in B and 10.2% in C.. Higher morbidity in younger patients could be due to a lower prevalence of easier-passing uric acid stones. The higher occurrence of urological disturbances and struvite stones in the elderly could explain the higher morbidity in this group.

Topics: Adult; Age of Onset; Aged; Calcium; Calcium Oxalate; Calcium Phosphates; Citric Acid; Comorbidity; Female; Humans; Hydrogen-Ion Concentration; Kidney Calculi; Kidney Function Tests; Magnesium Compounds; Male; Middle Aged; Oxalic Acid; Phosphates; Prevalence; Pyelonephritis; Recurrence; Retrospective Studies; Struvite; Uric Acid; Urinary Tract; Urinary Tract Infections

The successful fragmentation of kidney stones by means of extracorporeal shock wave lithotripsy partly depends on stone composition. In case of incomplete or coarse fragmentation, multiple urological procedures following ESWL may be necessary for removal of obstructive fragments. It is difficult to be sure that a given stone will be successfully destroyed. X-ray examinations before treatment are useful to classify calculi as calcium stones or not. Nevertheless, such investigations are often not sufficient to identify the main crystalline phases which form the stone and that can make it either resistant or friable to ESWL.. The aim of this study was to compare crystalluria and stone composition in patients with kidney calculi.. Seventy-five untreated patients (54 males, 21 females) were included. Their first morning urine was collected three days before surgical removal of the stone. Urine samples were kept at 4 degrees C during 48 hours before examination.. Crystalluria occurred in 97.3% of urine specimens. Weddellite was the most frequent crystalline species found in urine (66.2%), followed by carbapatite (33.1%) and whewellite (23.1%). When compared to stone composition, crystalluria was mainly made of weddellite in urines from 68% of patients with weddellite-rich calculi. Stones from patients presenting with whewellite crystals in urine were mainly composed of whewellite in 88.9% of cases. Struvite stones were associated with struvite and carbapatite crystalluria in 85.7% of cases.. Crystalluria studies could be of clinical interest to predict the main crystalline phase of calcium-containing stones in order to define the best procedures for stone removal.

Topics: Adult; Calcium Oxalate; Calcium Phosphates; Crystallization; Female; Humans; Kidney Calculi; Magnesium Compounds; Male; Microscopy, Polarization; Middle Aged; Phosphates; Spectrophotometry, Infrared; Struvite; Uric Acid

Struvite precipitation and urease activity were studied in 72 bacterial strains isolated from patients with an urinary infection. The results revealed struvite precipitation by urease-positive, urease-negative and weakly urealitic bacteria. However, in some strains of each of these groups, no precipitation was observed. Variations in pH within the cultures were also investigated as were the mineralogy and morphology of the crystals precipitated using X-ray diffraction and scanning electron microscopy, respectively. The role of urease activity and alkalinization of the medium in struvite precipitation is discussed, as is the possible involvement of bacteria in nucleation processes. We concluded that urease-negative bacteria or those with weak urease activity may also be involved in the formation of struvite renal calculi although urease-positive bacteria seem to make a greater contribution.

Topics: Chemical Precipitation; Crystallization; Humans; Hydrogen-Ion Concentration; Kidney Calculi; Magnesium Compounds; Microscopy, Electron, Scanning; Phosphates; Struvite; Urease; Urinary Tract Infections

To assess the role of primary open surgery versus the recommended combination approach (percutaneous and lithotripsy) to treat staghorn calculi in a developing country.. Available records (n = 91) of patients with staghorn managed during the last 4 years were retrieved. Patients were placed in two groups, open surgery and combination group, according to the primary procedure chosen by the patient. Demographic data in two groups was comparable in most of the respects except that renal failure patients were more in the combination group. Stone clearance, major residue, auxiliary procedures, morbidity, hospital stay and the cost were studied in the two groups for comparison.. Complete clearance could be obtained in 66 and 59% with open and combination method respectively. Major residue (> 16 mm2) was present in 21% of open and 38% of the combination group. In patients with primary stone burden < 900 mm2, the total clearance rates were 66 and 60% in open and combination group, respectively. Total clearance was not affected by caliceal dilatation, total stone burden, pelvic and caliceal bulk separately or their ratio, as arrived by logistic regression analysis. The incidence of haematuria in the combination group was marginally higher, probably due to more renal failure patients in this group. Hospital stay in the two groups was comparable (13.0 days in combination vs. 12.1 days for open). The cost of treatment with combination group was significantly higher.. Open surgery for staghorn is still an economically viable option for difficult stone disease, specially in a developing country, with comparable efficacy, favourable morbidity and hospital stay.

Topics: Adult; Case-Control Studies; Developing Countries; Female; Hospital Charges; Humans; India; Kidney Calculi; Length of Stay; Lithotripsy; Logistic Models; Magnesium Compounds; Male; Middle Aged; Phosphates; Struvite

Topics: Artifacts; Calcium Oxalate; Calcium Phosphates; Colorimetry; Cystine; Humans; Kidney Calculi; Magnesium Compounds; Phosphates; Reagent Kits, Diagnostic; Reproducibility of Results; Sensitivity and Specificity; Spectrophotometry, Infrared; Struvite; Uric Acid

We report a case of bilateral struvite and matrix staghorn calculi in a quadriplegic man with severe upper and lower extremity contractures that prevented percutaneous nephrolithotomy. Bilateral ureteroscopic lithotripsy was performed but the "snowstorm" of particles and viscous matrix material prevented complete stone clearance with the ureteroscope alone. Irrigation and aspiration through a fluoroscopically positioned nasogastric tube allowed evacuation of stone debris, mucinous matrix, and completion of the procedure.

Topics: Humans; Intubation, Gastrointestinal; Kidney Calculi; Kidney Calices; Lithotripsy, Laser; Magnesium Compounds; Male; Middle Aged; Phosphates; Struvite; Suction

Topographic features of eight struvite calculi were investigated with scanning electron microscopy (SEM) equipped with energy-dispersive X-ray microanalysis (EDX). Perpendicularly cracked fragments showed concentric laminations composed of compact and loosely packed strata alternately. Magnesium and phosphorus were detected in the compact strata with their characteristic dispersive X-ray spectra. There existed numerous spherular crystals with smooth or porous surfaces and scattered penta- or hexa-hedral coffin-lid shaped crystals in the loosely packed strata. The former crystals showed the dispersive X-ray spectra of calcium and phosphorus, and were estimated to be calcium phosphate (CaP). The latter ones were presumed to be magnesium ammonium phosphate (MAP) with EDX. The surfaces of the fragments were cracked like eggshells and displayed numerous CaP crystals and scattered MAP crystals in most cases, while in only 1 case some faces of pieces demonstrated wavy MAP phases, sundry areas which were rimmed with aggregated CaP spherulites. The mean molar ratios of Mg/P and Ca/P in each case were 0.88-1.03 and 1.25-1.52, respectively. Though EDX was inadequate to determine the accurate chemical formula of CaP and MAP crystals by detecting their molar ratios of Ca/P and Mg/P with EDX, SEM/EDX is useful to observe these urolith crystals and to surmise them to be CaP or MAP crystals by detecting their atomic elements with EDX.

Topics: Adult; Aged; Electron Probe Microanalysis; Female; Humans; Kidney Calculi; Magnesium Compounds; Male; Microscopy, Electron, Scanning; Middle Aged; Phosphates; Struvite; Urinary Bladder Calculi

This study was designed to assess the effect of i.v. treatment with aminophylline (AMPH) on the risk of calcium phosphate and struvite stone formation. We administered AMPH in doses of 4 mg/kg body weight in 15-min i.v. infusions to 60 infants with clinical symptoms of obstructive bronchitis with dyspnoea. During 3 hours after infusion we observed a significant increase in urine saturation with brushite, octocalcium phosphate and struvite. This rise in urine saturation may increase the risk of kidney stone formation.

Topics: Aminophylline; Bronchitis; Bronchodilator Agents; Calcium Phosphates; Dyspnea; Humans; Hydrogen-Ion Concentration; Infant; Infusions, Intravenous; Kidney Calculi; Magnesium Compounds; Male; Phosphates; Risk Factors; Struvite

We analyzed a series of 61 stones from children aged 3 to 14 years old using Fourier transform infrared spectroscopy. The calculi were collected from urology departments of the University Hospitals of Oran, Sidi-Bel-Abbès and Mostaganem in West Algeria. This series is the first investigation concerning the composition of stones in children based on infrared analysis. Calculi were more frequent in males (75.4%) and mainly localized in the bladder (55.8%). Upper urinary tract calculi were more frequent in children over the age of 10 years, and the sex ratio was about 1. Calcium oxalate monohydrate was present in 70.5% of stones and was the main component in 50.8% of cases both in whole stones and nuclei. In contrast, calcium oxalate dihydrate was the main component in only 9.8% of calculi although it was present in 75.4% of stones. Ammonium urate was detected in 29.5% of stones and was always the main component of nuclei. Uric acid, observed in 31.1% of calculi, was the major constituent in 14.7% of stones and 19.7% of nuclei. Magnesium ammonium phosphate was observed in 24.6% of stones as a consequence of urinary tract infection by urea-splitting bacteria. Our observations emphasized that the anatomical location of stone and their composition were in accordance with those previously reported in other countries.

Topics: Adolescent; Age Factors; Algeria; Calcium Oxalate; Child; Child, Preschool; Female; Humans; Kidney Calculi; Magnesium Compounds; Male; Phosphates; Sex Factors; Spectrum Analysis; Struvite; Ureteral Calculi; Uric Acid; Urinary Bladder Calculi; Urinary Calculi

In regard to identify the compositions of urinary stones, the infrared spectra is a contemporary routine method. However, it is difficult to detect the absorption of carbonate in struvite stone by infrared spectra, because NH4 absorption of magnesium ammonium phosphate overlaps CO3 absorption of carbonate at 1420-1435 cm-1. With the purpose of demonstrating the existence of carbonate in struvite stones, the analysis of these stones by means of Raman spectra has been tried.. Forty urinary stones, the chemical compositions of which were previously determined by infrared spectroscopy, were submitted to Raman spectrum analysis, and subsequently to analysis by x-ray diffraction.. Thirty of 40 urinary stones were found to be composed of struvite and of mixed struvite-calcium oxalate by infrared analysis. Twelve of these stones were shown to have Raman spectra of magnesium ammonium phosphate, and the other stones to have spectra of apatite. By x-ray diffraction magnesium ammonium phosphate crystals were detected in 25 of these struvite stones and hydroxyl-apatite in another 3, and 2 cases were undeterminable. For other components, such as calcium oxalate, uric acid and cystine, the analytical results of infrared spectra coincided with those of Raman spectra and x-ray diffraction. Carbonate was detected in only a part of one struvite stone by Raman spectra.. Above-mentioned results may indicate that carbonate is only a minor component of urinary stones. Therefore, most of 1420-1435 cm-1 bands on the infrared spectra of struvite stones do not indicate CO3 absorption of carbonate, but NH(4) absorption of magnesium ammonium phosphate.

Topics: Calcium Oxalate; Carbonates; Female; Hemostatics; Humans; Kidney Calculi; Magnesium Compounds; Male; Phosphates; Spectrophotometry, Infrared; Spectrum Analysis, Raman; Struvite; Urinary Calculi; X-Ray Diffraction

We determined the long-term prognosis of the pediatric patient presenting with simultaneous ureteropelvic junction obstruction and a renal calculus.. We retrospectively reviewed all individuals younger than 17 years who presented to our institutions with simultaneous ureteropelvic junction obstruction and an ipsilateral renal calculus.. Simultaneous ureteropelvic junction obstruction with nonstruvite calculi was present in 22 patients, while 6 had struvite calculi. Median age at diagnosis was 11 years (range 5 to 16). During a median followup of 9 years (range 2 to 38) renal calculi recurred in 19 patients (68%), including 10 (36%) with 1 and 9 (32%) with 2 or more recurrences. Median time to first stone recurrence was 11 years (range 2 to 38). Of the 22 patients with nonstruvite calculi 15 (68%) had recurrence. An identifiable metabolic etiology for renal lithiasis was found in 13 of these patients (87%). In contrast, only 2 of the 7 patients (29%) with nonstruvite calculi and no recurrent stones had an identifiable abnormality. This finding suggests that the presence of an identifiable metabolic abnormality significantly predisposes to recurrent nonstruvite renal lithiasis (p < 0.01).. Of the pediatric patients presenting with simultaneous ureteropelvic junction obstruction and a renal calculus 68% will have recurrent renal lithiasis. It remains to be determined whether active treatment of coexisting metabolic abnormalities could prevent or reduce the incidence of recurrent stone disease.

Topics: Adolescent; Child; Child, Preschool; Follow-Up Studies; Humans; Kidney Calculi; Kidney Pelvis; Magnesium Compounds; Phosphates; Prognosis; Recurrence; Retrospective Studies; Struvite; Time Factors; Ureteral Obstruction

This study presents the results of a 10-year metaphylaxis of 19 former struvite stone formers, each having had 2-3 stone operations. In these patients, urine was acidified with L-methionine (Acimethin) using a dose of three to six tablets 500 mg/day. Every three months, 11 laboratory parameters were checked in 24-hour urine. 6 parameters were determined in serum. In addition, urine samples were tested for infection. Statistical analysis of analytical data, which was supported by computer graphs, provided the results for the urinary parameters. They were described by geometric means and 95% confidence intervals using ANOVA (analysis of variance). During therapy, the mean pH values decreased significantly from 7.5 to 5.5. Signific-ant increases were found in the excretion of citrate, magnesium, potassium, and uric acid. An increase was also found for calcium, which, however, could not be confirmed to be statistically significant (p = 0.08). In serum, changes of parameters could only be registered for calcium and phosphate. However, at all times, total serum concentrations stayed within their normal limits. Three patients suffered occasional infections (16%), only two of them formed recurrent stones (10%). In assessing the efficacy of L-methionine therapy, the drop in urinary pH to acidic values was the most relevant factor for metaphylaxis.

Topics: Analysis of Variance; Bacterial Infections; Calcium; Chemoprevention; Citrates; Citric Acid; Creatinine; Female; Follow-Up Studies; Humans; Hydrogen-Ion Concentration; Kidney Calculi; Longitudinal Studies; Magnesium; Magnesium Compounds; Male; Methionine; Middle Aged; Phosphates; Potassium; Recurrence; Struvite; Uric Acid

Phosphates precipitating from artificial urine in the pH range 6-8 were identified using X-ray diffraction, chemical analysis and scanning electron microscopy. The influence of magnesium and citrate on phases precipitating from urine was established. From urine containing a normal quantity of magnesium (around 70 ppm), brushite accompanied by hydroxyapatite (HAP) precipitated at pH < or = 7.0 and struvite with HAP at pH > 7.0. HAP was formed exclusively from magnesium deficient urine at pH 7.0. Newberyite, octacalcium phosphate and whitlockite were not identified. The chemical and phase composition and inner fine structure of 14 phosphate calculi were studied. Three types of stones were distinguished based on their magnesium content: (i) stones rich in magnesium composed of struvite, hydroxyapatite and abundant organic matter, (ii) stones with low magnesium content constituted by calcium deficient hydroxyapatite, up to 5% of struvite, considerable amount of organic matter and occasionally brushite, and (iii) calculi without magnesium consisting of brushite, hydroxyapatite and little organic matter. Conditions prevaling during stone-formation assessed for each type of stone were confirmed by corresponding urinary biochemical data and corroborate the in vitro studies of phosphates precipitation.

Topics: Calcium Phosphates; Chemical Precipitation; Crystallization; Kidney Calculi; Magnesium Compounds; Phosphates; Struvite

We reviewed 111 patients who presented with simultaneous renal calculi and a ureteropelvic junction obstruction. Of 34 patients with ureteropelvic junction obstruction and a coexisting struvite stone 62% had recurrent calculi. The use of antibiotics significantly affected the incidence of recurrent struvite calculi. In particular, if prolonged prophylactic antibiotics (greater than 3 months) were used 15% of the patients had recurrent stones, compared to 90% if only perioperative antibiotics (less than 15 days) were used (p < 0.001). Patients with ureteropelvic junction obstruction and coexisting nonstruvite calculi were treated by either observation alone (53) or metabolic evaluation with appropriate intervention (24). Metabolic evaluation of patients with nonstruvite calculi revealed that 76% had an identifiable metabolic abnormality, treatment of which significantly decreased the incidence of recurrent renal calculi: 17% of the patients on interventional therapy had recurrent stones compared to 55% treated by observation alone (p < 0.001).

Topics: Anti-Bacterial Agents; Female; Follow-Up Studies; Humans; Kidney Calculi; Magnesium Compounds; Male; Metabolic Diseases; Phosphates; Recurrence; Struvite; Time Factors; Ureteral Obstruction

Topics: Adult; Bacteremia; Corynebacterium; Corynebacterium Infections; Follow-Up Studies; Humans; Kidney Calculi; Magnesium Compounds; Male; Phosphates; Recurrence; Struvite

Detailed metabolic evaluation and prophylaxis for all patients presenting with a first renal stone seems inappropriate. The crucial clinical problem lies in predicting which patients are likely to have a recurrence. Stone composition is an important guide for the physician's decisions concerning investigation and a rational choice of treatment.

Topics: Calcium; Cystinuria; Humans; Kidney Calculi; Magnesium Compounds; Phosphates; Recurrence; Struvite; Uric Acid

Density and content of mineral constituents were determined for 33 human calcium oxalate monohydrate (hereafter COM) uroliths whose external appearance and inner structure were described in part I and II respectively. Studied stones contained 0.13-0.42 wt.% of struvite, 0.68-4.12 wt.% of hydroxyapatite, 73-96 wt.% of COM and 3-10 wt.% of water unbound in a crystallohydrate 10 to 20 wt.% of calculus mass is not accounted for by chemical analysis. Density of COM calculi varying between 1.67 and 2.06 g cm-3 is not a function of any single stone parameter. Around 30% of stone volume is not occupied by crystalline components. The mulberry stones of sedimentary origin contained higher amount of organic matter than papillar and mulberry stones displaying site of attachment to epithelium.

Topics: Calcium Oxalate; Densitometry; Durapatite; Humans; Kidney Calculi; Magnesium Compounds; Minerals; Phosphates; Struvite

Topics: Bone Neoplasms; Calcium Oxalate; Cystine; Hardness; Humans; Kidney Calculi; Kinetics; Magnesium Compounds; Phosphates; Preoperative Care; Radionuclide Imaging; Struvite; Technetium Tc 99m Medronate; Uric Acid; Urinary Calculi

The identification of calcium-binding proteins in urine and kidney stones has led to a closer look at the role of matrix proteins in urolithiasis. We analyzed five struvite stones for protein content and identified two bands (8 and 14 KDa) that were confirmed by gel electrophoresis and amino acid sequencing to be calgranulin. This protein, which is known by several other names, has bacteriostatic antifungal activity. Its role in the formation of struvite stones warrants further investigation.

Topics: Amino Acid Sequence; Calcium-Binding Proteins; Cell Adhesion Molecules, Neuronal; Electrophoresis; Enzyme-Linked Immunosorbent Assay; Humans; Kidney Calculi; Leukocyte L1 Antigen Complex; Magnesium Compounds; Molecular Sequence Data; Phosphates; Struvite

Topics: Chronic Disease; Humans; Kidney Calculi; Magnesium Compounds; Male; Middle Aged; Phosphates; Proteus Infections; Struvite; Urinary Tract Infections

In vitro studies have demonstrated that trace elements have inhibitory as well as stimulatory effects on the crystallization of urinary stones. Little is known about the activities of rare-earth elements (REEs) in the human body. Although their physiological role is unclear, an effect on calcium transport mechanisms is discussed. In the present study, ten kidney stones (six oxalate and four phosphate stones) were analyzed by neutron-activation analysis for their REE patterns. Urinary stones are capable of concentrating these elements, and some fractionation into light and heavy REEs appears to take place during deposition. Significantly elevated concentrations of heavy REEs such as europium, terbium, and lutetium were detected in phosphate stones as compared with oxalate stones (P < 0.005).

Topics: Calcium Oxalate; Calcium Phosphates; Europium; Humans; Kidney Calculi; Lutetium; Magnesium Compounds; Metals, Rare Earth; Neutron Activation Analysis; Phosphates; Struvite; Terbium

Most staghorn calculi are infection stones composed of struvite and/or carbonate apatite. Sometimes, cystine, uric acid, whewellite and brushite stones also assume a staghorn configuration when located in the kidney. It is very important in stone crushing to know the composition and architecture of the stones. Struvite stones show a concentric laminal structure and are fragile because of wide interstices of crystals and rich organic matrix. These stones usually contain many bacterial colonies in the interstices of crystals and bacteria break out of the stones when they are crushed. Therefore, perioperative administration of antibiotics is necessary for prevention of bacteremia and sepsis. Whewellite stones and uric acid stones have a smooth surface and reveal compact radial and laminal structure especially in the peripheral layer. They are very hard and are refractory to crushing, and the fragments are large. Cystine stones show a compact radial monomineral texture and are very hard. The fragments made by crushing are large. Therefore, combination therapy of stone crushing and irrigation of alkali solution may be useful for treatment of cystine stones as well as uric acid stones. Calcium phosphate stones, hydroxyapatite or brushite stones, are rare and are formed in hyperparathyroidism, Cushing syndrome and renal tubular acidosis. Hydroxyapatite stones are rich in matrix and fragile. Brushite stones reveal radiate structure and are hard. There is no general method of treatment for staghorn calculi but we should select the most reasonable method including open surgery for each case taking into consideration the stone composition, predisposing factors and possibility of stone residue and recurrence.

Topics: Apatites; Calcium Phosphates; Cystine; Humans; Kidney Calculi; Lithotripsy; Magnesium Compounds; Phosphates; Struvite; Uric Acid

Between May 1989 and November 1991, 19 staghorn calculi were treated by extracorporeal shock-wave lithotripsy (ESWL) with a Dornier MFL 5000 or Northgate SD-3. The 19 calculi were evaluated. Treatment was with monotherapy by ESWL in 9, combination percutaneous nephrolithotomy (PNL)-ESWL in 9, and nephrostomy in 1. Of the patients, 14 had a cross stent catheter pre-ESWL treatment to improve fragment evacuation. Radiologic follow up in 19 kidneys revealed that 57.9% were stone free. We arbitrarily separated our cases into 3 groups: struvite renal calculi, calcium carbonate calculi and others. Result of stone-free rate was 100% for stones consisting of struvite, and 14. 3% for stones consisting of calcium carbonate. In our opinion, the best indication of monotherapy by ESWL is for staghorn calculi, which consists of struvite, without marked dilation of pelvis and calyces.

Topics: Adult; Aged; Calcium Carbonate; Combined Modality Therapy; Female; Humans; Kidney Calculi; Lithotripsy; Magnesium Compounds; Male; Middle Aged; Nephrostomy, Percutaneous; Phosphates; Struvite

Out of 500 Iranian sheep examined, six revealed the presence of lithiasis in their kidneys. Nephroliths in three animals were composed of ammonium magnesium phosphates and in the others of calcium carbonates and calcium phosphates. Interestingly sodium and ammonium urate crystals were present in the kidneys of three animals.

Topics: Abattoirs; Animals; Calcium Carbonate; Calcium Phosphates; Iran; Kidney Calculi; Magnesium Compounds; Phosphates; Sheep; Sheep Diseases; Struvite

Topics: Calcium Oxalate; Hardness; Humans; Kidney Calculi; Lithotripsy; Magnesium Compounds; Phosphates; Radiography; Struvite; Ureteral Calculi; Uric Acid

Of 100 renal units which were made stone-free by percutaneous stone extraction in 1985, 86 (86.0%) were re-examined radiologically up to 5 years after operation. The re-examination was performed because of symptoms or as part of a regular check-up or after calling the patient. Intrarenal calcifications were diagnosed in 27 of 86 (31.4%) of the renal units, but only in 11 (12.8%) were there stones requiring treatment.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Calcium Oxalate; Calcium Phosphates; Cystinuria; Female; Follow-Up Studies; Humans; Kidney Calculi; Lithotripsy; Magnesium; Magnesium Compounds; Male; Middle Aged; Nephrostomy, Percutaneous; Phosphates; Radiography; Radioisotope Renography; Recurrence; Struvite; Urinary Tract Infections

Topics: Corynebacterium Infections; Humans; Kidney Calculi; Magnesium; Magnesium Compounds; Phosphates; Struvite; Urinary Tract Infections

A variable pressure volumetric pump was used for 10% hemiacidrin irrigation of the renal pelvis in 7 renal units (6 patients) with struvite calculi after initial percutaneous debulking and extracorporeal shock-wave lithotripsy (ESWL). The pump provided a constant display of intrapelvic infusion pressure, and an alarm which signaled if a preset maximum infusion pressure was exceeded. Compared with standard open manometer monitoring of intrapelvic pressure, this closed system of irrigation eliminates the problems associated with time-consuming assembly and maintenance, irrigant spillage, and system contamination. At the completion of therapy, 5 renal units were completely stone-free while 2 had only minimal residual caliceal "dust." Complications were minor and few in number. We conclude that a variable pressure volumetric pump provides excellent clinical results and safely simplifies irrigation for percutaneous chemolysis of struvite calculi.

Topics: Citrates; Female; Humans; Infusion Pumps; Kidney Calculi; Kidney Pelvis; Lithotripsy; Magnesium; Magnesium Compounds; Male; Middle Aged; Pharmaceutic Aids; Phosphates; Struvite; Therapeutic Irrigation

The composition of 2,755 calculi obtained from the upper urinary tract (1,409 by spontaneous passage and 1,346 by urological procedures) was analyzed using an infrared spectrophotometer, and the spontaneous passage rate was investigated in relation to the composition as well as other variables, such as stone size, and patient age and sex. Mixed stones of calcium oxalate and calcium phosphate were most frequently found, followed by those of calcium oxalate. The mean size (the maximum diameter) was largest in struvite stones and smallest in calcium oxalate ones. The sizes of stones from women were significantly larger than those from men (p < 0.01). As expected, the stone passage rates were inversely related to increasing stone size. The size of 55.6% of the stones passed was < or = 5 mm, and that of 96.6% of the stones < or = 10 mm.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Calcium Oxalate; Calcium Phosphates; Child; Child, Preschool; Cystine; Female; Humans; Infant; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Spectrophotometry, Infrared; Struvite; Ureteral Calculi; Uric Acid

A total of 28 patients with extensive struvite staghorn calculi underwent endourological sandwich therapy consisting of primary percutaneous debulking followed by extracorporeal shock wave lithotripsy (ESWL*) of residual stone fragments. Secondary percutaneous procedures, ESWL treatments and 10% hemiacidrin irrigations were used as necessary specifically to achieve a stone-free renal unit. With 12 to 55 months (mean 31 months) of followup, during which time regular surveillance was done and antibiotic prophylaxis was used routinely, renal function remained stable or improved in 93% of the patients, including 4 with a solitary kidney. Infection has recurred or persisted in 30% of the patients, while stones recurred in 22%. We conclude that an aggressive, combined endourological approach to the management of struvite staghorn calculi can achieve long-term results comparable to standard operative intervention.

Topics: Combined Modality Therapy; Creatinine; Follow-Up Studies; Humans; Kidney Calculi; Lithotripsy; Magnesium; Magnesium Compounds; Phosphates; Recurrence; Struvite; Time Factors; Urinary Tract Infections

We evaluated the respective role of size, location and composition of renal stones as determinants of the outcome of extracorporeal shock wave lithotripsy (ESWL). The analysis of the chemical composition and of the morphology of the fragments eliminated by hundred patients who underwent ESWL has been made by X-rays diffraction. Results showed that the larger the stone, the higher the risk of having to perform an extra intervention (additional sessions of ESWL, percutaneous nephrostolithotomy, nephrolitholapaxy) or of finding residual fragments at the three month check-point. In addition, the location of the stone in a calice, especially a lower calice, strongly predisposes to incomplete elimination of the fragments. Finally, two types of stones appear to lessen the probability of success of ESWL: those of struvite and those of cystine. Indeed, out of eleven ESWL performed on struvite stones (pure or mixed), two had to be completed by percutaneous nephrolitholapaxy and even one by a nephrectomy because of superinfection. Out of the four patients with cystine stones, two had to be treated by additional percutaneous nephrolitholapaxy because of inadequate fragmentation after ESWL. However, for the remaining types of stones (pure or mixed) chemical composition seems to be less important than size or location.

Topics: Cystine; Female; Humans; Kidney Calculi; Lithotripsy; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Struvite; X-Ray Diffraction

Struvite stones are caused by urea-splitting, usually gram-negative, organisms. A case of aggressive struvite stone production caused by Corynebacterium group F1 is reported that responded to the appropriate antibiotic treatment. To our knowledge this organism has never been associated previously with struvite stone formation.

Topics: Adult; Corynebacterium Infections; Humans; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Phosphates; Struvite; Urinary Tract Infections

A retrospective study was done on 64 patients who received staged extracorporeal shock wave lithotripsy (ESWL) monotherapy for complete renal staghorn calculi. We used laboratory-proven stone components and a regular postoperative follow-up for a minimum of 6 months. There were 46 women and 18 men. The ages ranged from 19 to 75 years (mean 48.5 years). The number of ESWL sessions ranged from 1 to 4, with a mean of 2.1 sessions. The mean cumulative hospital stay was 13.3 days (range: 6-26 days). Successful treatments were defined as debulking over 90% of the stone burden and residual fragments of less than 3 mm in the longest diameter without obstruction 6 months post-treatment. A success rate of 86% was achieved in patients who had normal or minimal hydrocalycosis and only a 14.3% success rate for the patients with moderate to severe hydrocalycosis (p less than 0.005). Five of the patients with radiant calcium oxalate monohydrate had an unfavorable outcome. The best results were observed in the patient group of magnesium ammonium phosphate/apatite with normal to minimal hydrocalycosis (94.4% successful). The stone-free rate in this series was 51.6% at 6 months posttreatment. Being the least invasive, staged ESWL monotherapy is one of the better alternatives for the treatment of complete renal staghorn calculi in a select patient group.

Topics: Adult; Aged; Apatites; Calcium Oxalate; Female; Follow-Up Studies; Humans; Kidney Calculi; Lithotripsy; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Radiography; Retrospective Studies; Struvite

To clarify the significance of retained stone particles after extracorporeal shock wave lithotripsy (ESWL) for struvite renal calculi we followed 22 otherwise healthy women for 16 to 52 months (mean 39 months). Each patient had persistent Proteus mirabilis bacteriuria before ESWL and received a standardized regimen of antimicrobial therapy in the perioperative period only. Of the 22 patients 19 (86%) were cured of the persistent bacteriuria. Of these 19 patients 16 had retained stone particles at the beginning of surveillance and 10 had retained particles at last followup. None of the particles produced symptoms or enlarged. However, 1 of the patients who was rendered stone-free had a P. mirabilis reinfection at 20 months and a new stone developed. Of the 22 patients 3 (14%) had continued persistent P. mirabilis bacteriuria after ESWL. Two patients were subsequently cured of the infection with antibiotics alone (1), and with antibiotics and extraction of a new ureteral stone (1). The remaining patient had expansion of retained stone particles after 51 months of surveillance. We conclude that a stone-free kidney is an unrealistic objective of ESWL monotherapy for struvite renal calculi. However, the treatment usually will eradicate the accompanying persistent bacteriuria and sterile stone particles will not enlarge during the first 2 to 4 years after treatment.

Topics: Adult; Aged; Bacteriuria; Female; Follow-Up Studies; Humans; Kidney Calculi; Lithotripsy; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Prospective Studies; Struvite

We reviewed 53 patients with infection stones treated by extracorporeal shock wave lithotripsy (ESWL*) monotherapy to determine the long-term rate free of stones and the stone recurrence rate as correlated with the pre-treatment stone burden and the radiological presence of sand or fragments after the procedure. Long-term followup (mean 26.6 months) was available on 33 patients representing 38 kidneys. Although only 3 kidneys were free of stones immediately after ESWL, 20 were without stones at 3 months and 18 (47%) were stone-free at followup. Of 9 kidneys with fragments of more than 5 mm. after the final treatment 7 (78%) had residual fragments at 3 months and experienced stone progression. Of 9 kidneys with sand remaining 6 (66%) and all 3 kidneys that appeared to be free of stones after ESWL were without stones at followup. The 3-month plain film of the kidneys, ureters and bladder was a reliable indicator of eventual outcome. Of 20 kidneys that were free of stones at 3 months 16 remained without stones. Of 18 kidneys with residual stone particles at 3 months 14 showed disease progression, 2 had stable disease and 2 passed residual sand. Only 1 of 17 patients who were free of stones or had stable stone disease had a positive urine culture at followup. Patients with infection stone fragments 3 months after ESWL monotherapy have a high rate of stone progression (78%) and should undergo further treatment. ESWL monotherapy of infection stones requires close patient followup to assure that all residual fragments have passed and urine remains sterile.

Topics: Adult; Aged; Apatites; Female; Follow-Up Studies; Humans; Kidney Calculi; Lithotripsy; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Radiography; Retrospective Studies; Struvite; Urinary Tract Infections

The pulsed dye laser represents a new tool in the treatment of ureteral calculi. Laser energy channeled through a delicate optical fiber is used to disimpact and fragment calculi. Standard ureteroscopic instruments including graspers, baskets and dilatation balloons can be used with the laser system. Interchangeable optical fibers ranging from 200 to 400 micrometers deliver up to 120 mJ of energy to the stone's surface. For two weeks in 1989 an endourology clinic was held in upper Egypt. Eighty patients ranging in age from nine years to sixty-seven years old were evaluated and treated endoscopically. Endoscopes ranging from 6.9F to 12.5F were used to deliver the optical fiber. All stones visualized endoscopically were fragmented. Greater than 60 percent of the stones fragmented were composed of pure calcium oxalate monohydrate. Schistosoma hematobium was endemic among our study group. Bilharzial strictures of the distal ureter were noted in 30 percent of these patients. Treatment of these strictures using both balloon dilatation and graduated Teflon dilators is reviewed. Techniques in treating different types of ureteral calculi were explored. Large calcium oxalate dihydrate stones were treated most efficiently with the 3-point fragmentation technique. The shear off-center technique was used for the calcium oxalate monohydrate calculi. Variations in total energy delivered and frequency of pulsation allowed for prompt stone disimpaction as well as prevention of retrograde fragment migration. Concurrent use of stone baskets and graspers with the pulsed dye laser was explored.

Topics: Adolescent; Adult; Aged; Calcium Oxalate; Catheterization; Child; Coloring Agents; Endoscopes; Endoscopy; Humans; Kidney Calculi; Kidney Calices; Laser Therapy; Lithotripsy; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Schistosomiasis; Struvite; Ureteral Calculi; Ureteral Obstruction; Uric Acid

The morphological and constitutional analysis of renal stone fragments expelled after extracorporeal shock wave lithotripsy enables the structure and morphological type of stones to be reconstructed in 92.8 per cent of the cases as regards surface and section and in 74.5 per cent of the cases down to the core. A study of the molecular and crystalline composition of such fragments demonstrated the preponderance of whewellite in both sexes (men 85.4 per cent; women 72.4 per cent). The frequency of weddellite was 1.6 times higher in men (73.8 per cent) than in women (44.8 per cent), and the frequencies of struvite and ammonium urate were 2.8 and 2.6 times respectively higher in women than in men, despite a significant fall in frequency as compared to a previous series. Correlations between morphological type of stone and biochemical data (when available) could be established in 84 per cent of the cases. This made it possible to initiate treatments aimed at preventing recurrences, the cost of these treatments in the long term being lower than that of the curative urological treatments, including extracorporeal shock wave lithotripsy.

Topics: Adult; Calcium Oxalate; Female; Hemostatics; Humans; Kidney Calculi; Lithotripsy; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Struvite; Uric Acid

At Osaka City University Hospital, we performed extracorporeal shock-wave lithotripsy (ESWL) for 1277 patients in a total of 1788 sessions using Dornier kidney lithotripter Model HM III from July, 1985 to the end of December, 1988. Among the patients with a solitary stone, 911 cases were available for the follow-up study and we have compared the results among these cases in respect to the stone location and size. The results obtained were as follows: the ratio of kidney stone to ureter stone was found to be 2.2:1 in male, and 3.8:1 in female patients. This indicates that ureter stones are more frequently found in male than in female patients. In addition, we compared the size of kidney stones found in the patients including 415 male and 243 female patients. Stones larger than 20 mm were more frequently found in female than in male patients. Moreover, a stone composition study of these patients showed that the contents of both phosphate calcium and magnesium ammonium phosphate were higher in female than in male patients. ESWL performed against stones at pelvis and calyces exhibited the best results. The results obtained with the stones less than 20 mm in diameter were especially favorable with a success rate of 100% for the stones less than 10 mm and 83% for the stones 10-20 mm, in diameter, while the results with the stones larger than 20 mm in diameter were rather poor with a success rate of 31%. ESWL performed against ureter stones showed poor results with a success rate of 63% for the stones smaller than 20 mm in diameter.

Topics: Calcium Phosphates; Evaluation Studies as Topic; Female; Humans; Kidney Calculi; Lithotripsy; Magnesium; Magnesium Compounds; Male; Phosphates; Sex Factors; Struvite; Ureteral Calculi

From December 1986 through March 1988, 52 renal units (RU) with large stone burden have been treated by ESWL monotherapy. In all patients a ureteral stent was placed prior to lithotripsy, to provide drainage of the kidney during the period of stone passage. Data of 43 RU were collected for the present report. Complications ; following treatment were infrequent (2%), whereas auxiliary measures became necessary in 32% of the patients. After a mean follow-up of 9.1 months, 54% of the patients were found stone-free. Stratification according to different stone types and compositions revealed that none of the 7 patients with complete staghorns could be completely cleared and that struvite stones had a significantly better outcome than calcium oxalate stones (75 vs. 25%). Consequently, for a large but not excessive stone burden in a normal or only slightly dilated renal collecting system, ESWL monotherapy under the protection of a ureteral stent may be a comparably safe alternative to percutaneous surgery.

Topics: Adult; Aged; Calcium; Humans; Kidney Calculi; Lithotripsy; Magnesium; Magnesium Compounds; Middle Aged; Phosphates; Stents; Struvite; Ureter

Two sets of experiments were carried out on 14 live rabbits having renal calculi from nephrolithiasis patients implanted in their kidneys. Shock waves were used to disintegrate the implanted concrements. It took 100 to 150 sound pulses to crush struvite stones to fragments less than 2 mm in size, with 400 to 800 pulses needed to destroy calcium oxalate stones. After multiple exposures to shock waves there were no indications of any gross damage to the soft tissues of the experimental animals. Mechanisms for destruction of kidney stones by shock waves were considered.

Topics: Animals; Calcium Oxalate; Kidney Calculi; Lithotripsy; Magnesium; Magnesium Compounds; Phosphates; Rabbits; Struvite

Routine thermogravimetric (TG) analysis of 501 upper urinary calculi from the State of Jammu and Kashmir is described. The technique is simple, rapid and quantitative, and the equipment is easily maintained. The technique was found to be helpful in 95.4% of urinary stones and it is suggested that TG analysis may be employed as a technique of first choice in the routine quantitative analysis of all urinary calculi.

Topics: Calcium Oxalate; Calcium Phosphates; Humans; Kidney Calculi; Magnesium; Magnesium Compounds; Phosphates; Struvite; Thermogravimetry; Ureteral Calculi

29 patients suffering from recurrent struvite stones and/or persistent urinary tract infection were analyzed retrospectively with a follow-up time of 10 +/- 6 years. A sanitation of the urease-positive urinary tract infection was possible in 12 patients (41%). After 10 out of 53 operations (19%) rest stones were found. An unilateral nephrectomy was done in 3 cases. Despite rest calculi and persistent urinary tract infection no further calculus growth or deterioration of renal function was found in most patients.

Topics: Combined Modality Therapy; Female; Follow-Up Studies; Humans; Kidney Calculi; Kidney Failure, Chronic; Magnesium; Magnesium Compounds; Male; Middle Aged; Nephrectomy; Phosphates; Postoperative Complications; Recurrence; Retrospective Studies; Struvite; Urinary Tract Infections

During a seven-year period (1975-1981) a total of 1325 patients hospitalized for stone disease were studied as to the occurrence of positive urine cultures. Urinary stones from 535 surgically treated patients were analyzed with infrared spectrophotometry and the relationships between stone composition, level of surgery and bacteriological strains were studied. Positive urinary cultures were found in 34% of the surgically treated patients and in 21% of those not operated upon. Among the surgically treated patients with urinary tract infection (UTI) E. coli was the most frequent microorganism (35%), followed by Proteus (28%). Patients with Proteus infection had the highest frequency of UTI episodes, most of which occurred before hospitalization. There was a higher frequency of magnesium ammonium phosphate (MAP) calculi among patients with Proteus infection than among those with non-Proteus infection, in whom no difference in stone composition was found. Patients infected with E. coli had more phosphate-containing stones (CaP+MAP) than non-infected patients. The highest frequency of oxalate calculi (CaOx+CaOx/CaP) was found among patients without infection. No E. coli infections were seen in male patients with CaP and MAP calculi. MAP stones were most often found in the kidney and oxalate stones in the ureter.

Topics: Calcium Oxalate; Calcium Phosphates; Escherichia coli Infections; Female; Humans; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Proteus Infections; Spectrophotometry, Infrared; Struvite; Urinary Tract Infections

The greater frequency of renal stones seen on excretory urograms in women, compared with the greater frequency of ureteral stones in men has been termed a sexual paradox. We assessed stone composition and weight, and sex as possible explanatory factors. A total of 4,014 renal and ureteral calculi was analyzed. For the 3,119 calculi in which only calcium oxalate and/or phosphate was detected by infrared and wet chemical analysis, there was a strong relationship between the oxalate-to-phosphate weight ratio and sex (p less than 0.0001). The mean weight for phosphate stones was 330 mg. but for oxalate stones it was 107 mg. Male-to-female ratios were 2.7, 2.2 and 1.8 for stone weight groups of 20 or less, 21 to 100 and more than 100 mg. The male-to-female ratio was 0.87 for the 171 stones containing magnesium ammonium phosphate; the average weight was 508 mg. for men and 1,560 mg. for women. The tendency for phosphate stones to be heavier and relatively more common in women compared to predominantly oxalate stones may partly account for the sexual paradox.

Topics: Calcium Oxalate; Calcium Phosphates; Female; Humans; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Phosphates; Sex Characteristics; Struvite; Ureteral Calculi

Topics: Calcium Oxalate; Calcium Phosphates; Corynebacterium; Crystallization; Humans; Kidney Calculi; Kidney Medulla; Magnesium; Magnesium Compounds; Phosphates; Struvite

With extensive analytical and clinical examinations it is shown that the proof of carbonate in apatite may allow no additional reference of an infection with urea-splitting bacteria. With certain analytical methods the presence of carbonate is demonstrable in each urinary calculus apatite phase. Carbonate-bearing apatite indeed is accompanied frequently with struvite, but may be occur also without an infection. Therefore, in the future it should be renounced on the differentiation of apatite and carbonate apatite in routine analyses of urinary calculi.

Topics: Apatites; Durapatite; Female; Humans; Hydroxyapatites; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Phosphates; Pyelonephritis; Struvite

Ten patients with complex struvite stones were treated successfully with primary extracorporeal shock wave lithotripsy followed by chemolysis with 10 per cent hemiacidrin renal irrigation. The average number of treatments per renal unit was 1.2 and an average of 2,688 shocks was administered per treatment. No patient required a blood transfusion. Ureteral obstruction did not occur in those patients receiving planned hemiacidrin irrigation immediately after extracorporeal shock wave lithotripsy. At 6-week followup 9 patients were free of residual fragments. The combination of extracorporeal shock wave lithotripsy and hemiacidrin chemolysis represents a satisfactory alternative to the traditional surgical management of complex struvite calculi.

Topics: Adult; Aged; Citrates; Female; Humans; Kidney Calculi; Lithotripsy; Magnesium; Magnesium Compounds; Male; Middle Aged; Pharmaceutic Aids; Phosphates; Radiography; Struvite; Therapeutic Irrigation; Ureteral Obstruction

Topics: Apatites; Follow-Up Studies; Humans; Kidney Calculi; Lithotripsy; Magnesium; Magnesium Compounds; Phosphates; Struvite

In 6 patients (9 kidneys) irrigation with Solution G in the renal pelvis was performed for the dissolution of their infectious stones. Staghorn calculi larger than 30 mm in diameter were observed in all patients. In two kidneys all stones were dissolved and the rest were dissolved into small fragments that constituted no problem in those kidneys. Irrigation was done with no major side effects or complications. The dissolution of infectious stones with Solution G is another possible treatment that could be first chosen among percutaneous nephrolithotripsy, extracorporeal shock wave lithotripsy and other treatments.

Topics: Adolescent; Adult; Aged; Calcium Carbonate; Carbonates; Citrates; Drug Combinations; Female; Humans; Kidney Calculi; Kidney Pelvis; Magnesium; Magnesium Compounds; Magnesium Oxide; Male; Middle Aged; Phosphates; Solutions; Struvite; Therapeutic Irrigation

Experimental irrigation of 15 infectious renal stones with hemiacidrin resulted in complete dissolution of 11 stones within 5 days. Three of the undissolved stones had a calcium oxalate (CaOx) content of more than 10%. Stones containing calcium phosphate (CaP) and magnesium ammonium phosphate (MAP) and weighing less than 500 mg were most easily dissolved. Twenty-five stones placed in 10 ml of hemiacidrin resulted in complete dissolution of 13 and partial dissolution of 11. Even this experiment showed that the CaOx content was of importance for the outcome of hemiacidrin treatment. After treatment the MAP and CaP fractions had decreased and CaOx increased. In 36 clinical irrigations of residual concrements of known chemical composition, 5 resulted in total stone dissolution and 21 in a reduced stone volume, whereas the result was inconclusive in 3. Seven stones were not affected by the treatment, these stones were usually composed of CaP and CaOx. There was a good correlation between the dissolution test and the clinical response to hemiacidrin treatment. Based on these findings it is suggested that hemiacidrin might be a useful complement to the modern techniques of stone fragmentation such as extracorporeal shock wave lithotripsy and percutaneous surgery, at least for infectious stones with a CaOx content of less than 10%.

Topics: Calcium Oxalate; Calcium Phosphates; Citrates; Female; Humans; In Vitro Techniques; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Nephrostomy, Percutaneous; Pharmaceutic Aids; Phosphates; Struvite; Therapeutic Irrigation

Topics: Apatites; Calcium Phosphates; Combined Modality Therapy; Humans; Kidney; Kidney Calculi; Magnesium; Magnesium Compounds; Oxalates; Phosphates; Struvite

The ESWL retreatment rates for calculi of 1.1 to 3.0 cm. varied according to stone composition: calcium oxalate monohydrate (COM) 10.3%, calcium oxalate dihydrate (COD) 2.8%, struvite/apatite calculi 6.4%. Fine detail in-vitro radiographs of approximately equal sized calculi composed of COM, COD, struvite, brushite, uric acid and cystine showed structural differences which may account for differences in their fragility. The same six calculi were fragmented in vitro in the Dornier HM3 lithotriptor by 200 shocks at 18 KV and the percent weight of each calculus able to be filtered through a two mm. sieve was determined; COD and uric acid (100%); COM (64%); struvite (57%); brushite (47%); cystine (16%). The linear density of these calculi, measured by single photon emission absorbtiometry, correlated with radio-density, not fragility. Calculi of varying composition respond differently to shock wave fragmentation. The assessment of the capability of ESWL to fragment a stone will determine the size stone selected for treatment. Therefore, "stone fragility" is a new distinction which deserves to be included in the conversation about urinary calculi.

Topics: Calcium Oxalate; Calcium Phosphates; Cystine; Humans; Kidney Calculi; Lithotripsy; Magnesium; Magnesium Compounds; Phosphates; Struvite; Uric Acid

Topics: Calcium Oxalate; Cation Exchange Resins; Durapatite; Humans; Hydroxyapatites; Ion Exchange Resins; Kidney Calculi; Magnesium; Magnesium Compounds; Phosphates; Struvite; Suspensions

Struvite nephrolithiasis is caused by infection with bacteria that possess the enzyme urease, and convert urea to ammonia that raises urine pH and crystallizes with magnesium and trivalent phosphate ion. Of the 75 of our 1431 stone patients with struvite stones 52 were women. Struvite stones occurred almost exclusively in women; a minority of women and most men had mixed stones of struvite and calcium oxalate. Increased serum creatinine levels and reduced creatinine clearance were common in patients with struvite stones, not in those with mixed stones; both were rare in calcium stone disease. Men and women with mixed struvite, calcium oxalate stones were hypercalciuric, but women with struvite stones were not. Patients with mixed stones usually had initial symptoms of stone passage, and were less likely to need surgery, including nephrectomy, or to form contralateral stones. Patients with struvite stones usually presented with infection or no symptom, not passage. We conclude that struvite stones occur in two forms. The struvite stone is a disease of women, presumably occurring de novo from infection. The mixed stones occur in both sexes, presumably from secondary infection in hypercalciuric patients who begin with calcium-oxalate stone disease.

Topics: Blood Pressure; Calcium; Female; Follow-Up Studies; Glomerular Filtration Rate; Humans; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Nephrectomy; Phosphates; Risk Factors; Struvite

CT examinations were conducted in 47 patients with staghorn calculi in the renal pelvis. Density measurements in the region of the calculus supplied pointers to the structure of the calculus.

Topics: Adult; Calcium Oxalate; Calcium Phosphates; Female; Humans; Kidney Calculi; Kidney Pelvis; Magnesium; Magnesium Compounds; Male; Phosphates; Struvite; Tomography, X-Ray Computed

Struvite calculi occurring in patients with chronic urinary tract infections consist of an inorganic component of magnesium ammonium phosphate crystals and an underlying organic mucopolysaccharide matrix. Shock waves used to destroy these stones during extracorporeal shock wave lithotripsy (ESWL) therapy may affect the inorganic and organic components of the stone differently. In a 26-year-old woman, renal obstruction resulted from retained struvite stone matrix after ESWL therapy.

Topics: Adult; Female; Humans; Kidney Calculi; Lithotripsy; Magnesium; Magnesium Compounds; Nephrostomy, Percutaneous; Phosphates; Struvite; Suction; Ureteral Obstruction

Despite Food and Drug Administration restrictions on its use above the ureterovesical junction, many investigators have used carefully monitored renal pelvic lavage with 10 per cent hemiacidrin for struvite calculi without serious side effects in hospitalized patients. We evaluated renal irrigations with hemiacidrin in 13 carefully selected patients (15 kidneys). In this high risk population (6 patients were paretic) initial treatment was done in the hospital but the remainder of 18 periods of extended renal perfusion (mean period 20 days) were performed at home. The total number of outpatient days of perfusion in this group was 365. All patients experienced external leakage around the perfusion catheter. Fever of greater than 101F occurred in 14 of 18 perfusions (78 per cent). Rehospitalization was necessary during 3 perfusions (17 per cent) and serum magnesium was elevated 3 times (17 per cent). Stones were dissolved successfully in 14 of 18 perfusions (78 per cent) but they recurred in 3 patients. No patient had altered post-perfusion serum creatinine levels. Outpatient perfusion of the renal pelvis with 10 per cent hemiacidrin under carefully controlled conditions appears to be a safe and cost-effective treatment for struvite or phosphate renal calculi.

Topics: Adult; Ambulatory Care; Apatites; Citrates; Female; Hospitalization; Humans; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Middle Aged; Nephrostomy, Percutaneous; Pharmaceutic Aids; Phosphates; Struvite; Therapeutic Irrigation

Urine alkalinization favours the formation of calcium phosphate (CaP) and struvite stones. In this retrospective study we analyze the effect of chronic urinary acidification on phosphatic stone recurrence. Twenty-four patients with CaP-struvite recurrent stones and persistently high urinary pH were divided in two groups: group A, 11 patients who failed to lower the urinary pH below 5.5 during a standard acid load test: group B, 13 patients with preserved acidification power. Ammonium sulfate 2-3 g/day was given for 4.7 and 6.5 years to groups A and B, respectively. A persistent reduction in urinary pH, relative saturation for CaP and stone formation rate was observed in both groups. The treatment did not cause systemic acidosis as long as renal function remained normal. Urinary daily excretion of Ca and P as well as their renal tubular handling did not change with time. Results suggest acidifying agents might be useful in preventing recurrence of CaP-struvite stones even in the presence of a mild acidification defect and encourage undertaking properly controlled prospective trials.

Topics: Adult; Ammonium Sulfate; Calcium Phosphates; Chronic Disease; Drug Evaluation; Female; Humans; Hydrogen-Ion Concentration; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Recurrence; Retrospective Studies; Struvite; Time Factors

Topics: Adult; Aged; Anti-Bacterial Agents; Drug Therapy, Combination; Female; Humans; Hydrogen-Ion Concentration; Hydroxamic Acids; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Struvite; Urease; Urinary Tract Infections

Topics: Adult; Anti-Infective Agents, Urinary; Calcium Oxalate; Female; Humans; Hydrogen-Ion Concentration; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Mandelic Acids; Methenamine; Middle Aged; Phosphates; Proteus Infections; Struvite; Urinary Tract Infections

The majority of staghorn calculi (branched calculi)--25 per cent bilateral--is mainly composed of calcium phosphates, in about 2/3 with varying fractions of Struvite. Pure Struvite stones are rare. Large fractions of Struvite form a soft concrement. Infection with urea splitting bacteria arises ascending, therefore predominantly in female kidneys, except for the first decennium. Staghorn calculi without Struvite (1/3 of our cases), show extremely large growth and sterile urine. Some Struvite stones have sterile urine or Struvite without urea splitting bacteria. The shape of branched calculi depends on the form of hilus renalis and the aggressiveness of the alkaline urine and the infection. Renal cirrhosis--almost always present--follows bacterial or abacterial obstruction, depending on the degree of vascular obliteration by reactive fibrosis of the intima, with or without pyonephrotic, xanthomatous necrosis, similar to renal tuberculosis. The so-called "large stone kidney" is obstructive, aseptic and lipomatous special form of staghorn calculus and cirrhosis. Stone formation and grade of cirrhosis may be determined by tomography.

Topics: Adult; Age Factors; Aged; Calcium Oxalate; Calcium Phosphates; Female; Humans; Kidney; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Sex Factors; Struvite; Urea

The effects of synthetic urine environments of pH 4, 6, and 9.5 on the microhardness of renal calculi have been investigated. Tests were made, using both Vickers and Knoop indenters, on three compositions of calculi: 100% calcium oxalate monohydrate (whewellite), 100% uric acid, and 98% magnesium ammonium phosphate hexahydrate (struvite) mixed with 2% carbonate apatite. Whewellite calculi hardness was lowered, relative to (dry) values by 45-55% when saturated with a solution of pH 9.5. Exposure to lower pH conditions was not as effective in lowering hardness in this case. Struvite calculi hardness was lowered by 41-52% compared to the dry hardness and uric acid calculi hardness decreased by 25-36%, compared to dry hardnesses. For uric acid stones the reduction in hardness did not depend on pH within the range of pH values investigated. For struvite stones, acid pH conditions appear to give an increased softening, compared to other pH values.

Topics: Biomechanical Phenomena; Calcium Oxalate; Humans; Hydrogen-Ion Concentration; In Vitro Techniques; Kidney Calculi; Magnesium; Magnesium Compounds; Phosphates; Struvite; Uric Acid

Based on the analysis of magnesium (Mg), ammonium (NH4), phosphate (P), urine pH, and urine volume (V), a simplified estimate (AP[MAP] index) of the ion-activity product of magnesium ammonium phosphate (AP MAP) was derived: (Formula: see text). The factor A varies according to the collection period. In 4-hour urine samples more than half of the patients with staghorn calculi had values above 5 in contrast to normal subjects and calcium oxalate stone formers in whom lower values apparently were the rule. The AP(MAP) index might be of value in the evaluation and follow-up of patients with staghorn calculous disease.

Topics: Calcium Oxalate; Chemical Phenomena; Chemistry; Humans; Hydrogen-Ion Concentration; Kidney Calculi; Magnesium; Magnesium Compounds; Phosphates; Struvite; Urinary Calculi

The use of drugs inhibiting bacterial urease represents an interesting improvement in preventive treatment of renal infected stones. The low dose (120 mg/day) for one week followed by 60 mg/day of propionohydroxamic acid (PHA) has shown excellent anti-urease activity. The nearly normal absence of side effects also allows long-term administration.

Topics: Humans; Hydroxamic Acids; Kidney Calculi; Magnesium; Magnesium Compounds; Phosphates; Struvite; Urinary Tract Infections

Thirty-three patients operated on for renal staghorn calculous disease were studied retrospectively with respect to urine and stone composition, bacteriuria, and abnormalities of the urinary tract. Calcium phosphate was the most common stone constituent, present in 30 of 31 concrements. Twenty-one of these stones also contained magnesium ammonium phosphate, despite the fact that only 10 patients had presented evidence of urinary tract infection during the initial period of the disease. Twenty-four-hour urine composition was normal in only 3 patients. In 59 per cent an increased CaOx risk index was observed suggesting that CaOx risk factors might contribute to the development of staghorn concrements. A metabolic evaluation of staghorn stone formers appears to be of importance for design of the postoperative treatment.

Topics: Adolescent; Adult; Bacteriuria; Calcium Oxalate; Calcium Phosphates; Female; Humans; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Risk; Struvite; Urologic Diseases

Over the last few years there have been marked advances in both the surgical and medical treatment of urinary stone disease. At present, we have expectations of decreasing the incidence of stone recurrence in a vast majority of patients with medical therapy alone. While there are still many patients who will continue to develop new stones, decreasing their rate of new stone formation will lessen the need for surgical intervention.

Topics: Calcium; Cystinuria; Fluid Therapy; Humans; Kidney Calculi; Magnesium; Magnesium Compounds; Phosphates; Risk; Struvite; Uric Acid; Urinary Calculi

Combinations of percutaneous and extracorporeal shock wave lithotripsy were performed on 46 patients with 52 staghorn calculi. Of the renal units 15 per cent had minute residual fragments but only 9.7 per cent with struvite had residual stones. The morbidity of this combined approach is less than that of anatrophic nephrolithotomy. We believe that the majority of staghorn calculi can be removed in this manner. Nephrostolithotomy should be the initial procedure in most instances. This less invasive approach is especially advantageous in patients at high risk for recurrence.

Topics: Adolescent; Adult; Aged; Female; Humans; Kidney Calculi; Lithotripsy; Magnesium; Magnesium Compounds; Male; Middle Aged; Nephrostomy, Percutaneous; Phosphates; Recurrence; Risk; Struvite

The pre-operative urine, pelvic urine, removed calculi and calculus washings were examined bacteriologically in 24 patients undergoing removal of intrarenal calculi. Four of seven patients with struvite calculi had an infected pre-operative midstream urine specimen and six of the seven removed calculi demonstrated significant bacterial growth. Proteus mirabilis was the commonest organism isolated. Of 17 patients with oxalate calculi only one had an infected pre-operative urine culture, but in four cases the removed stones were infected. Quantitative bacteriological culture of the stones and their washings demonstrated that infection is within the stone itself. Pre-operative urine culture failed to predict infection within the stone in 60% of patients with infected stones. The results suggest that the presence of infected urine together with the presence of renal calculus is indication for removal of the calculus.

Topics: Adult; Aged; Bacteriuria; Enterobacteriaceae Infections; Enterococcus faecalis; Escherichia coli; Female; Humans; Kidney Calculi; Klebsiella pneumoniae; Magnesium; Magnesium Compounds; Male; Middle Aged; Oxalates; Oxalic Acid; Phosphates; Proteus; Pseudomonas aeruginosa; Pseudomonas Infections; Staphylococcal Infections; Staphylococcus aureus; Streptococcal Infections; Struvite

Topics: Adult; Aged; Calcium; Female; Humans; Hydrogen-Ion Concentration; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Middle Aged; Oxalates; Parathyroid Hormone; Phosphates; Struvite; Uric Acid

Renal stone disease is a common problem in patients with spinal cord injury. The factors responsible are thought to include hypercalciuria and chronic urinary infection. There have, however, been no comparative studies of urinary composition in patients with neuropathic bladder with and without renal stone disease. Blood, 24-h urine samples and circadian variation of urinary composition were studied in male paraplegic patients with renal stone disease accompanied by urinary infection and in similar patients without stone disease with and without urinary infection. Two categories of stone patients were recognised, according to whether or not urinary oversaturation with magnesium ammonium phosphate occurred. The urine of all stone patients was oversaturated with calcium phosphate for part of each day. Urinary calcium was elevated in 16% and plasma urate in 30% of the paraplegics studied.

Topics: Adolescent; Adult; Aged; Calcium; Circadian Rhythm; Humans; Hydrogen-Ion Concentration; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Middle Aged; Paraplegia; Phosphates; Struvite; Urinary Tract Infections

We have investigated and treated 176 patients who were suffering from renal calculi. The stones contained calcium in 87% of patients, predominantly urate in 11%, and rarely contained magnesium ammonium phosphate or cystine. Of the patients with calcium stones, hypercalciuria was present in 75% and was identified in 57% by the measurement of the 24-hour urinary calcium excretion, and in a further 18% by a standardization calcium "fast-and-load" test. Nine patients were found to have primary hyperparathyroidism and were treated surgically. A further 21% were suspected to have normocalcaemic hyperparathyroidism, and metabolic studies are being developed to clarify this. The treatment of hypercalciuria included a low-calcium diet, and various combinations of a thiazide diuretic, phosphate supplements and sodium cellulose phosphate. Hypercalciuria was controlled in all compliant patients, and only two developed further stones. Hyperuricosuria was rarely the sole metabolic abnormality in patients with calcium stones, though this might reflect the referral pattern of the Unit. Uric acid stones were frequently, but not invariably, associated with hyperuricosuria and acid urine, and even large uric acid calculi dissolved with a combined therapy of high fluid intake, allopurinol and an alkalinizing agent. Surgical treatment was rarely required in these patients. A stone in the renal pelvis of one patient was removed percutaneously and did not require ultrasonic fragmentation. Modern methods of investigation and treatment have greatly improved the outlook for patients with recurrent renal calculi.

Topics: Calcium; Chronic Disease; Combined Modality Therapy; Female; Humans; Hyperparathyroidism; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Recurrence; Struvite; Uric Acid

From the analysis of various urinary constituents and the estimation of urinary saturation of stone-forming salts, it is now possible to identify risk factors responsible for or contributing to stone formation. Metabolic factors included calcium, oxalate, uric acid, citrate and pH. Environmental factors were total volume, sodium, sulfate, phosphate and magnesium. Physicochemical factors represented saturation of calcium oxalate, brushite, monosodium urate, struvite and uric acid. A scheme for graphic display of risk factors was developed to allow ready visual recognition of important risk factors presumed to cause stone formation. This graphic display had diagnostic use as well as practical value in following response to treatment. For example, a low urinary pH and high urinary concentration of undissociated uric acid could be discerned readily in cases of uric acid lithiasis, as were high urinary pH and exaggerated urinary supersaturation of struvite in cases of infection lithiasis. In a patient with absorptive hypercalciuria and hypocitraturia treatment with thiazide and potassium citrate could be shown to abolish high risks (hypercalciuria, hypocitraturia and relative supersaturation of calcium oxalate) displayed before treatment.

Topics: Calcium; Calcium Oxalate; Calcium Phosphates; Citrates; Citric Acid; Humans; Hydrochlorothiazide; Hydrogen-Ion Concentration; Kidney Calculi; Magnesium; Magnesium Compounds; Oxalates; Oxalic Acid; Phosphates; Risk; Struvite; Uric Acid

We report the results of 1,000 consecutive patients who underwent percutaneous removal of renal and ureteral stones. Removal was successful for 98.3 per cent of the targeted renal stones and 88.2 per cent of the ureteral stones. Complications, evolution and technique are discussed. Percutaneous techniques are an effective way to handle the majority of renal calculi and these techniques will continue to be important as shock wave lithotripsy becomes more widespread in the United States.

Topics: Blood Transfusion; Cystine; Female; Hemorrhage; Humans; Intraoperative Complications; Kidney; Kidney Calculi; Length of Stay; Lithotripsy; Magnesium; Magnesium Compounds; Male; Nephrostomy, Percutaneous; Phosphates; Postoperative Complications; Struvite; Time Factors; Ureteral Calculi

To study the process of formation of staghorn calculi, 58 patients with staghorn calculi were evaluated clinically and the removed stones were studied architecturally. Of 35 patients with infection stones composed of struvite and/or apatite in the nuclei as well as peripheral layers, 18 had identified predisposing factors related to infection. Of 13 patients with infection stones containing calcium oxalate in the nuclei, 7 had predisposing factors of infection but only 2 had metabolic disorders. The patients with infection stones who had no predisposing factors may have transient or subclinical abnormalities. Initial stone formation of oxalate may also be one of the predisposing factors of infection. Most of the patients with staghorn calculi composed of uric acid, oxalate and cystine, had metabolic disorders related to these substances. Large numbers of bacteria and large amounts of organic matrix were found extensively within infection stones and were thought to be important components as well as crystals. Metabolic stones contained little matrix. In this case crystal aggregation is thought to play the most important role in stone formation.

Topics: Adolescent; Adult; Aged; Apatites; Calcium Oxalate; Child; Child, Preschool; Cystine; Female; Humans; Infant; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Struvite; Uric Acid; Urinary Bladder Diseases; Urinary Tract Infections; Vesico-Ureteral Reflux

Topics: Bicarbonates; Cystinuria; Humans; Kidney Calculi; Magnesium; Magnesium Compounds; Phosphates; Sodium Bicarbonate; Solubility; Struvite; Ultrasonic Therapy; Uric Acid; Urinary Bladder Calculi; Vibration

In 18 patients (20 kidneys) with struvite/apatite-, uric acid- and cystine stones antegrade local chemolysis was performed via percutaneous or operative nephrostomy. Complete stone dissolution was achieved in 11 kidneys, while in six kidneys partial dissolution of stones was performed. In these six cases added instrumental manipulations shortened the time of therapy. In three cases chemolysis was unsuccessful. Average irrigation time was 21 days per renal unit. Only minor complications like dysuria and skin rashes were seen. Due to long time of irrigation we recommend chemolitholysis mainly as an additional form of therapy in case of residual stones after operative or percutaneous nephrolithotomy.

Topics: Acetylcysteine; Apatites; Bicarbonates; Citrates; Combined Modality Therapy; Cystine; Female; Humans; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Recurrence; Sodium Bicarbonate; Struvite; Therapeutic Irrigation; Uric Acid

The bacteriological status of the pre-operative urine, removed calcium and the pelvic urine was studied in 63 consecutive patients undergoing removal of intrarenal calculi. The overall infection rates in the pre-operative urine, removed calculi and pelvic urine were 29%, 38% and 30% respectively. In patients with staghorn calculi, 58% of patients had an infected pre-operative M.S.S.U., and 82.5% of removed calculi demonstrated significant bacterial growth, with Proteus mirabilis being the predominant organism isolated. In patients with single or multiple oxalate calculi, 17% had an infected pre-operative M.S.S.U., and 22% of removed calculi demonstrated a significant bacterial growth. The findings would indicate that the presence of a positive M.S.S.U. in a patient with a renal calculus is an indication for surgical removal.

Topics: Adult; Aged; Bacteriuria; Female; Humans; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Middle Aged; Oxalates; Phosphates; Proteus mirabilis; Struvite

We determined the bacteriology of apparently infected renal calculi and accompanying urinary tract infections, and assessed the potential clinical value of the culture results. Twenty-two branched renal calculi from 16 patients were cultured. Fifteen calculi were infected with 1 or more urease-producing gram-negative enteric bacterium, 2 were infected with a urease-producing bacterium and a nonurease-producing organism, and 5 were sterile. Immersion of infected stones in antimicrobial solutions before culture reduced or eliminated surface bacteria but usually did not eradicate bacteria within the stone. The bacteriology of a stone or stones could be predicted on the basis of available urine culture results in only 2 of the 16 cases. These data suggest that branched renal calculi associated with bacteriuria usually are infected but that documentation of infection and identification of the infecting organism require culture of the stone.

Topics: Anti-Bacterial Agents; Apatites; Bacteriuria; Female; Humans; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Methods; Phosphates; Proteus mirabilis; Pseudomonas aeruginosa; Struvite; Urease; Urinary Tract Infections

Topics: Humans; Hydroxamic Acids; Kidney Calculi; Magnesium; Magnesium Compounds; Phosphates; Struvite; Urinary Tract Infections

Prevention of the formation of struvite and carbonate-apatite calculi, which rapidly increase in size and tend to recur, is of prime importance. One of the urease inhibitors, hydroxycarbamide, was studied in vitro. The results are favourable and justify further studies aimed at the local application of the inhibitor.

Topics: Ammonia; Apatites; Bacteriuria; Carbonates; Dose-Response Relationship, Drug; Humans; Hydrogen-Ion Concentration; Hydroxyurea; Kidney Calculi; Magnesium; Magnesium Compounds; Phosphates; Proteus Infections; Struvite; Urease

The chemical composition of 125 urinary stones was determined by means of an infrared spectrophotometric method using the potassium bromide pellet technique. Statistical combinations regarding the chemical composition of the stones are discussed and compared with the findings of other workers. Calcium oxalate was the commonest component of pure as well as mixed stones.

Topics: Apatites; Calcium Carbonate; Calcium Oxalate; Calcium Phosphates; Child; Humans; Kidney Calculi; Magnesium; Magnesium Compounds; Phosphates; Spectrophotometry, Infrared; Struvite; Uric Acid

Topics: Acinonyx; Animals; Animals, Zoo; Carnivora; Cats; Dogs; Hemostatics; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Phosphates; Struvite; Ureter; Ureteral Calculi

The formation of some urinary tract stones (struvite stones) is known to be related to infection by urease-possessing microorganisms, such as Proteus sp. and some other bacteria. Ureaplasma urealyticum, a genital mycoplasma, contains also urease and is predominantly located in the urogenital tract. Its significance in the production of human urinary stones has not yet been elucidated. In this study, 135 human calculi obtained by surgery were analysed chemically and were cultured for the presence of conventional bacteria and U. urealyticum, 51 were ammonium magnesium phosphate stones and contained Proteus (27), E. coli (4), Staphylococcus epidermidis (3), Streptococcus D (2), Pseudomonas aeruginosa (1), Staphylococcus aureus (1), Corynebacterium (1), Candida albicans (1). U. urealyticum was isolated in one patient, from two different calculi (left and right) taken after an interval of fifteen days. Different bacteria were isolated from other calculi (oxalate, uric acid). This findings suggest that Ureaplasma urealyticum should be looked for in struvite calculi.

Topics: Bacteria; Bacterial Infections; Calcium Oxalate; Humans; Kidney Calculi; Magnesium; Magnesium Compounds; Mycoplasmatales Infections; Phosphates; Struvite; Ureaplasma; Uric Acid

An in vitro study sought to determine the feasibility of using computed tomography (CT) to analyze the chemical composition of renal calculi and thus aid in selecting the best treatment method. Sixty-three coded calculi were scanned in a water bath. Region-of-interest measurements provided the mean, standard deviation, and minimum and maximum pixel values for each stone. These parameters were correlated with aspects of the stones' chemical composition. A multivariate analysis showed that the mean and standard deviation of the stones' pixel values were the best CT parameters for differentiating types of renal calculi. By using computerized mapping techniques, uric acid calculi could be perfectly differentiated from struvite and calcium oxalate calculi. The latter two types also were differentiable, but to a lesser extent. CT has a potential role as an adjunct to clinical and laboratory methods for determining the chemical composition of renal calculi in an effort to select optimal treatment.

Topics: Calcium Oxalate; Humans; Kidney Calculi; Magnesium; Magnesium Compounds; Phosphates; Struvite; Tomography, X-Ray Computed; Uric Acid

Percutaneous nephrostomy and hemiacidrin were used as primary treatment of magnesium ammonium phosphate calculi in 32 surgical candidates. Of 28 patients who actually received hemiacidrin 24 (85 per cent) had successful treatment (no surgery necessary), including 19 (68 per cent) who had total stone dissolution. There were no significant complications. Patients have been followed for 3 months to 7 years. Percutaneous nephrostomy with hemiacidrin infusion is another possible treatment in the growing alternatives available for patients with urinary struvite calculi.

Topics: Citrates; Humans; Kidney; Kidney Calculi; Magnesium; Magnesium Compounds; Phosphates; Postoperative Complications; Punctures; Radiography; Solubility; Struvite; Therapeutic Irrigation

Urolithiasis involving the upper urinary tract is a multifactorial disease that remains a significant health problem. A variety of intrinsic and extrinsic factors influence the incidence of disease in individuals and in all populations. At the level of the kidney, natural physicochemical processes result in crystalluria and the formation and growth of stones. Urinary supersaturation of some degree must be present but its significance may be altered by changes in urinary volume, pH, epitaxial relationships, and the presence or absence of naturally occurring inhibitors. A variety of environmental parameters acting through effects on the local urinary conditions determine which patients among a group of people inherently at risk will form stones. The above factors are considered herein with regard to the four major types of stone disease encountered today.

Topics: Adult; Calcium Oxalate; Crystallization; Cystine; Female; Humans; Hydrogen-Ion Concentration; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Phosphates; Risk; Sex Factors; Struvite; Uric Acid; Urinary Tract Infections

Most staghorn calculi occur in patients who have chronic urinary tract infections with urea-splitting organisms. Acetohydroxamic acid, an inhibitor of the bacterial urease enzyme, is currently undergoing clinical trials to determine whether or not it can prevent stone growth in patients at risk. We report on a patient whose stones grew while she was taking placebo and then decreased in size when she took the active drug.

Topics: Administration, Oral; Adult; Colic; Female; Humans; Hydroxamic Acids; Kidney; Kidney Calculi; Kidney Diseases; Magnesium; Magnesium Compounds; Phosphates; Proteus Infections; Proteus mirabilis; Radiography; Recurrence; Solubility; Struvite

The mineral composition of 103 stones from Iran was determined by a polarisation microscope and infrared spectroscopy. The commonest components were whewellite (81.5%), weddellite (40.7%), apatite (69%) and ammonium acid urate (24.4%). Ectopic cossification in the nuclei was found in three renal calculi (2.9%). Twenty-five stones were from children, where one of the most frequent patterns was formed by both ammonium acid urate and calcium oxalate. This suggests that a high proportion of the children from Iran with urolithiasis have nutritional disorders.

Topics: Adult; Calcium Oxalate; Calcium Phosphates; Child; Female; Humans; Hydroxyapatites; Iran; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Microscopy, Polarization; Minerals; Phosphates; Spectrophotometry, Infrared; Struvite; Uric Acid; Urinary Bladder Calculi

Renacidin (10 per cent hemiacidrin) irrigation has been used in the management of renal struvite calculi in 25 patients. Of these patients 22 were free of stone after irrigation: 16 after dissolution of residual stone fragments postoperatively, 4 after prophylactic postoperative irrigation and 2 after primary, nonsurgical percutaneous dissolution. Recurrent urinary tract infections owing to the original urease-producing bacteria occurred in 14 per cent of these patients and recurrent nephrolithiasis occurred in 9 per cent during an average followup period of 66 months.

Topics: Adult; Aged; Citrates; Female; Follow-Up Studies; Humans; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Middle Aged; Pharmaceutic Aids; Phosphates; Recurrence; Struvite; Therapeutic Irrigation; Time Factors

During a 5 year period, 500 stones from the upper urinary tract and 100 from the urinary bladder of as many unselected and consecutive patients were obtained in one hospital and analysed crystallographically. 90.4% of the upper urinary tract stones and 65% of the bladder stones belonged to the groups of calcium stones, while 6.6% and 24%, respectively, were triple phosphate stones. The contribution of calcium stones to this material is higher and that of triple phosphate stones lower than in comparable materials. Frequency variations between materials also exist within the groups of calcium stones, and for uric acid, urate and cystine stones. On the basis of published material, it is not possible to say if these differences are renal or reflect variations in the selection of stones and the methods of analysis. Reports on stone materials should include information on these aspects in order to allow meaningful comparison. Distinction between stones from the upper urinary tract and from the bladder is mandatory. The composition pattern reported here is believed to be as representative as is possible to obtain. A major part of stones from the upper urinary tract is, however, lost for analysis following spontaneous passage. Such stones are more often pure calcium oxalate and less often triple phosphate stones than those which are obtained by surgical methods, and the extent to which they are obtained will influence the findings in stone materials.

Topics: Adult; Aged; Calcium Carbonate; Calcium Oxalate; Calcium Phosphates; Crystallography; Cystine; Female; Humans; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Struvite; Ureteral Calculi; Uric Acid; Urinary Bladder Calculi; Urinary Calculi

Topics: Calcium Oxalate; Calcium Phosphates; Cystinuria; Humans; Hydrogen-Ion Concentration; Kidney Calculi; Magnesium; Magnesium Compounds; Phosphates; Struvite; Uric Acid

Topics: Apatites; Bicarbonates; Calcium Oxalate; Citrates; Cystine; Humans; Kidney Calculi; Magnesium; Magnesium Compounds; Pharmaceutic Aids; Phosphates; Solubility; Solutions; Struvite; Therapeutic Irrigation; Tromethamine; Uric Acid

Topics: Animals; Disease Models, Animal; Disease Susceptibility; Dog Diseases; Dogs; Kidney Calculi; Magnesium; Magnesium Compounds; Phosphates; Proteus Infections; Proteus mirabilis; Quaternary Ammonium Compounds; Radiography; Staphylococcal Infections; Struvite; Urinary Bladder; Urinary Tract Infections

We analyzed 48 renal calculi by X-ray powder diffraction and electron microprobe techniques. In 35 of these, the presence of a minor constituent, not detected by X-ray diffraction, was revealed--hydroxyapatite was found in 24 stones, struvite in 6, and calcium oxalate in 5. The results of this study, as well as others, show that incomplete assignment of the crystalline constituents of urinary calculi is an inherent risk of the X-ray method and that conclusions concerning total chemical composition should be based on X-ray diffraction analyses coupled with data obtained from other analytical procedures.

Topics: Calcium Oxalate; Electron Probe Microanalysis; Hydroxyapatites; Kidney Calculi; Magnesium; Magnesium Compounds; Phosphates; Struvite; X-Ray Diffraction

Topics: Calcium; Calcium Oxalate; Cystine; Humans; Hydroxyapatites; Kidney Calculi; Magnesium; Magnesium Compounds; Phosphates; Struvite; Uric Acid

The results of chemical analyses of 429 urinary calculi are presented and classified according to chemical composition. Some of the general features of the different chemical types of the stones are discussed. Although the general distribution of the chemical types of stones in Lebanon is essentially similar to that reported from other countries, the two striking features of this series are: (1) a relatively lower incidence of infection stones (i.e. stones containing magnesium ammonium phosphate) and (2) a relatively higher incidence of stones containing a mixture of uric acid and calcium oxalate and/or calcium phosphate.

Topics: Calcium Oxalate; Calcium Phosphates; Cystine; Humans; Incidence; Kidney Calculi; Lebanon; Lithotripsy; Magnesium Compounds; Phosphates; Struvite; Uric Acid; Urinary Calculi

We assessed beta 2-microglobulin excretion in 42 active calcium oxalate stone-formers, 16 active struvite stone-formers, 4 active uric acid stone-formers, 14 inactive stone-formers and 21 non-stone-forming controls. The average excretion value was within normal limits for all groups and no significant differences existed. These observations coupled with previous findings of increased low molecular weight urinary proteins in active calcium oxalate stone-formers suggest the existence of specific alterations in tubular function in this specific group.

Topics: beta 2-Microglobulin; Beta-Globulins; Calcium Oxalate; Escherichia coli; Female; Humans; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Phosphates; Proteus mirabilis; Pseudomonas; Quaternary Ammonium Compounds; Struvite; Uric Acid; Urine

The size distribution of the mineral phases in three renal stones (whewellite, struvite, and whitlockite) was determined using a particle-counting technique after removal of the organic matrix. The multisized crystallites of the investigated stones revealed close similarity in size distribution characteristics. Whewellite size parameters were in good agreement with the parameters of calcium oxalate monohydrate crystals formed in the kidneys of rats injected with L-4-hydroxyproline. However, these parameters differed significantly from the values calculated from the size distribution of calcium oxalate crystals voided in the urine of recurrent stone formers. The data obtained suggest that critical size distribution characteristics may be instrumental in causing the mineral phase to agglomerate and adopt a close packing in renal stones.

Topics: Animals; Calcium Oxalate; Calcium Phosphates; Hydroxyproline; Kidney Calculi; Magnesium; Magnesium Compounds; Particle Size; Phosphates; Quaternary Ammonium Compounds; Rats; Struvite

Urease positive staphylococcal urinary tract infection was experimentally induced in 13 dogs. Eight dogs developed cystic and/or urethral struvite calculi in 2 to 8 weeks. No abnormalities in systemic cell mediated immunity were detected in dogs before or after the establishment of the urinary tract infection. Miniature schnauzers whose ancestors had developed stones seemed to be no more susceptible to experimental urinary tract infection and stone formation than miniature schnauzers or beagles whose ancestors did not develop stones.

Topics: Animals; Dog Diseases; Dogs; Female; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Phosphates; Quaternary Ammonium Compounds; Staphylococcal Infections; Struvite; Urethral Diseases; Urinary Bladder Calculi; Urinary Calculi; Urinary Tract Infections