sodium-pertechnetate-tc-99m and Hypertension--Portal

To evaluate trans-splenic portal scintigraphy (TSPS) and per-rectal portal scintigraphy (PRPS) for diagnosis of congenital portosystemic shunts (CPSS) in dogs, and compare these results with surgical findings.. Prospective, randomized cross over clinical trial.. Dogs (n=42) with suspected CPSS.. Dogs had TSPS and PRPS 48 hours apart; quantity of radionuclide administered was recorded. Three independent, blinded reviewers evaluated each scintigraphic study for study quality, shunt presence, number, and location of shunt termination (caudal vena cava, azygos vein). All dogs had exploratory celiotomy. Negative scintigraphic findings were confirmed with intraoperative mesenteric portography. Ameroid constrictors were placed on all extrahepatic CPSS, and hepatic biopsies were obtained.. TSPS was 100% sensitive and specific for diagnosis of CPSS and significantly (P<.05) more likely than PRPS to detect shunt number and termination. Interpretation was consistent between observers, and TSPS required significantly less radionuclide than PRPS.. TSPS was as sensitive as PRPS for detection of shunting vessels, and consistently yielded studies of higher quality, allowing detection of shunt number and location with consistent interpretation among radiologists.. TSPS provides information about shunt number and location, which allows improved surgical planning. Because it requires significantly less radionuclide, TSPS improves safety, allows for more comprehensive patient care, and earlier surgical intervention.

Topics: Animals; Cross-Over Studies; Diagnosis, Differential; Dog Diseases; Dogs; Female; Hypertension, Portal; Male; Portal System; Predictive Value of Tests; Prospective Studies; Radionuclide Imaging; Radiopharmaceuticals; Sensitivity and Specificity; Sodium Pertechnetate Tc 99m; Spleen

We evaluated the clinical usefulness of 99mTc-pertechnetate per-rectal portal scintigraphy (PPS) in the assessment of portal circulation in children with chronic cholestasis.. PPS percentage shunt index (%SI) (the amount of radionuclide that shunts the liver and reaches the systemic blood after injection in the rectum) was measured in 22 children (mean age, 7.2 +/- 4.9 y) and compared with established clinical, laboratory, and endoscopic and imaging parameters of portal hypertension (PH). Fourteen children had surgically treated biliary atresia, and 8 had chronic intrahepatic cholestasis. Six clinically well children served as control subjects.. The %SI was 14.3 +/- 3.1 and 34.7 +/- 18.8 in controls and in patients, respectively (P < 0.01). A cutoff of 19% correctly allocated 100% of controls and 86% of patients. Mean %SI values were significantly higher in patients with biliary atresia, a high risk of pretransplantation death, esophageal varices (EV) at endoscopy, and an abnormal value for the ratio of lesser omentum thickness to abdominal aorta diameter (LO/Ao) at ultrasonography. Correlations between %SI values and several ultrasonographic continuous variables were statistically significant only for LO/Ao ratios (r = 0.51; P = 0.005) and spleen longitudinal diameters (r = 0.53; P = 0.01). The presence of EV could correctly be predicted only when values of %SI were greater than 30% (100% specificity; 56% sensitivity). Endoscopic and PPS findings agreed for a diagnosis of PH with EV in 3 of 7 patients with normal or borderline ultrasonographic LO/Ao ratios. PPS patterns and %SI values became normal in 3 children who underwent liver transplantation.. In children with chronic cholestasis, PPS may be an advantageous, minimally invasive tool complementary to ultrasonography and endoscopy for better assessment and follow-up of PH before and after liver transplantation.

Topics: Adolescent; Child; Child, Preschool; Cholestasis; Chronic Disease; Endoscopy, Digestive System; Female; Humans; Hypertension, Portal; Infant; Male; Portal System; Radionuclide Imaging; Radiopharmaceuticals; Rectum; Reproducibility of Results; Sensitivity and Specificity; Sodium Pertechnetate Tc 99m; Ultrasonography

This randomized double-blind controlled study analyzed the hemodynamic effects of penbutolol, a new levo-rotatory betablocker, using radionuclide angiography. Twenty cirrhotics with esophageal varices were randomized: 10 received 40 mg/day of penbutolol orally and the others a placebo. Angioscintigraphy was performed before and after an 8-day treatment period. Three cases in the penbutolol group were lost due to software damage, hence the data of 17 patients were analyzed. The two groups were similar for age, sex, etiology of cirrhosis and hepatic function. The index of portal perfusion decreased significantly (-29%; p = 0.018), and the hepatic artery index increased significantly (+23%; p = 0.018), whereas no changes were observed after placebo. The heart rate decreased significantly after penbutolol (-9%; p = 0.021); while neither penbutolol nor placebo modified the ejection fraction. In conclusion, penbutolol decreased portal perfusion index (the compensatory increase of hepatic artery index confirmed this change) without significant modification of total hepatic blood flow and systemic hemodynamics. Angioscintigraphy is reasonably accurate, reproducible, safe and can be considered suitable for routine use in the assessment of liver hemodynamics.

Topics: Administration, Oral; Double-Blind Method; Hemodynamics; Humans; Hypertension, Portal; Liver; Liver Circulation; Liver Cirrhosis; Penbutolol; Radionuclide Angiography; Sodium Pertechnetate Tc 99m

Variceal haemorrhage is a potentially life-threatening complication in cirrhotic patients. Identification of patients at high risk for bleeding is particularly important. The aim of this study was to determine the clinical usefulness of per-rectal portal scintigraphy (PPS) in the evaluation of the severity of portal hypertension in cirrhotic patients, in terms of correlation between cirrhosis and the parameters of hepatic functional reserve, and identifying the difference of the portal shunt index (PSI) of the bleeding oesophageal variceal (BEV) patients and non-BEV patients.. Portal circulations in 67 patients with cirrhosis and oesophageal varices were evaluated by Tc-99m pertechnetate PPS. Tc-99m pertechnetate (550 MBq) was instilled into the upper rectum, and dynamic images of upper abdomen were taken. Radioactivity curves for the liver and the heart were generated sequentially. Through the analysis of these curves, the PSI was determined.. The results, expressed as PSI, were: 11.4 +/- 98.4 percent (mean 66.8) in all 67 cirrhotic patients, 56.4 +/- 27.1 percent in cirrhotic patients without history of BEV, and 74.9 +/- 13.6 percent in cirrhotic patients with history of BEV. The PSI was significantly lower in cirrhotic patients without BEV than those with BEV (p-value equals 0.001). The PSI calculated with this method was correlated with the serum albumin, the serum bilirubin, the prothrombin time, and the Child-Turcotte-Pugh score.. Tc-99m pertechnetate PPS has clinical usefulness as a noninvasive method of choice for quantitatively evaluating the severity of portal hypertension in cirrhotic patients.

Topics: Administration, Rectal; Adult; Cohort Studies; Female; Humans; Hypertension, Portal; Liver Cirrhosis; Liver Function Tests; Male; Middle Aged; Portasystemic Shunt, Surgical; Probability; Radionuclide Imaging; Radiopharmaceuticals; Risk Assessment; Sensitivity and Specificity; Severity of Illness Index; Sodium Pertechnetate Tc 99m

Portal circulation, in particular the contribution of the inferior mesenteric vein, can be evaluated in a relatively noninvasive way by per rectal portal scintigraphy (J Nucl Med 1988; 29:460-5). The clinical usefulness of the method was evaluated.. A solution containing technitium-99m pertechnetate was instilled into the rectum, and serial scintigrams were taken while radioactivity curves for the liver and heart were recorded sequentially. By analyses of the curves, the per rectal portal shunt index (SI) was calculated.. The SI was higher for disorders that were more severe, increasing in the order of chronic persistent hepatitis, chronic aggressive hepatitis, and cirrhosis, and the SI was higher in cirrhotic patients than in patients with chronic hepatitis or in healthy subjects. The SI was significantly higher when a complication (varices, ascites, or encephalopathy) was present. Correlation between the SI and classic indicators for functional reserve was significant. The SI was significantly related to survival according to results of regression analysis by Cox's proportional hazards model. On the basis of the SI when patients were first examined, the patients with cirrhosis were divided into three groups of roughly equal size: group A, SI under 30%; group B, SI between 30 and 70%; and group C, SI over 70%. The survival rate was lower in group B than in A, lower in group C than in A, and lower in group C than in B.. This method is clinically useful, especially in establishing the prognosis.

Topics: Humans; Hypertension, Portal; Liver Cirrhosis; Liver Diseases; Liver Function Tests; Portal System; Prognosis; Proportional Hazards Models; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Survival Rate

Propranolol can reduce portal hypertension, therefore is recommended in prevention of variceal bleeding in patients with liver cirrhosis. However, in certain patients with cirrhosis portal hypotensive effect of propranolol cannot be obtained, and the reason of this finding is unknown. In 28 patients with cirrhosis the effect of seven days administration of propranolol on collateral blood flow from inferior mesenteric vein was examined by means of per-rectal portal scintigraphy. Portosystemic shunt index was significantly reduced by propranolol by 17.4 +/- 4.8%. This reduction was observed in cirrhotics classified to A and B, but not C Child-Pugh. These data suggest that propranolol increases vascular resistance in portosystemic circulation which depends on severity of liver failure. This mechanism opposes reduction of portal pressure.

Topics: Adult; Aged; Blood Pressure; Collateral Circulation; Esophageal and Gastric Varices; Female; Gastrointestinal Hemorrhage; Humans; Hypertension, Portal; Liver Cirrhosis; Male; Middle Aged; Portal System; Propranolol; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Vascular Resistance

Per-rectal portal scintigraphy with Tc-99m pertechnetate is a method to evaluate portosystemic shunting (shunt index) in inferior mesenteric vein. In this study the shunt index was estimated in patients with chronic liver disease in relation to the severity of liver injury, portal hypertension and incidence of oesophageal varices. Shunt index was elevated in patients with non-cirrhotic liver disease as compared with healthy normals (34 +/- 6% vs 8 +/- 2%; p < 0.0005). Moreover, patients with cirrhosis had the shunt index of 65 +/- 4% which was higher than in other groups. There was no correlation of the shunt index to the Child-Pugh classification, hepatic venous pressure gradient and varices size in the cirrhotic patients. Conversely, the shunt index differentiated variceal bleeders from non-bleeders (80 +/- 4% vx 59 +/- 6%; p < 0.005). These data show that peripheral collateral circulation develop in response to mild elevation of portal pressure, but its hemodynamic efficacy to alleviate portal hypertension seems to be unremarkable. High shunt index might reflect elevated risk of bleeding from varices.

Topics: Adult; Aged; Chronic Disease; Esophageal and Gastric Varices; Female; Gastrointestinal Hemorrhage; Hemodynamics; Humans; Hypertension, Portal; Liver Diseases; Male; Mesenteric Veins; Middle Aged; Radionuclide Imaging; Rectum; Sodium Pertechnetate Tc 99m

The reliability of HPI measurement was studied in animal experiment. The portal vein of experimental dogs was narrowed by application of a metallic coil. The induced portal hypertension with important hepatofugal collaterals appeared to be a suitable model for the study of changes in HPI. A decrease in the index was statistically significant and corresponded to the hemodynamical efficiency of collateral circulation. The original experiment verified the reliability of HPI for an assessment of direct perfusion of the liver by portal blood.

Topics: Animals; Collateral Circulation; Dogs; Hypertension, Portal; Liver Circulation; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

Topics: Bile; Cholestasis; Humans; Hypertension, Portal; Imino Acids; Liver Circulation; Liver Diseases; Organotechnetium Compounds; Portal System; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Technetium Tc 99m Lidofenin

Portosystemic shunt fraction estimation using transcolonic iodine-123-iodoamphetamine (IMP) has been previously validated relative to portal vein macroaggregated albumin injections using an experimental model of cirrhosis. Transcolonic technetium-99m-pertechnetate (TcO4-) has been proposed as an alternative tracer to IMP to study portal circulation in cirrhotic patients. We compared shunt fraction estimates from paired transcolonic IMP and TcO4- studies performed on a group of dogs before and after common bile duct ligation surgery. Pertechnetate over-estimated shunt fraction in 6/7 postoperative studies relative to IMP. A good correlation between the two methods was demonstrated, however, the slope of the regression line was substantially less than 1.0 with TcO4- values reaching 100% at IMP shunt values of approximately 60%. This apparent inability to accurately assess high shunt flows may limit the quantitative aspects of TcO4- studies on patients with severe portosystemic shunting.

Topics: Amphetamines; Animals; Dogs; Hypertension, Portal; Iodine Radioisotopes; Liver Cirrhosis, Biliary; Portal System; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

Portal circulation in patients with chronic liver diseases was evaluated by [99mTc]pertechnetate per-rectal scintigraphy. Technetium-99m pertechnetate (10 mCi) was instilled into the upper rectum, and serial scintigrams were taken. Radioactivity curves for the liver and heart were then recorded sequentially. Through analysis of these curves, the per-rectal portal shunt index (Sl) was calculated for six healthy subjects and 228 patients, 59 with chronic hepatitis, seven with idiopathic portal hypertension, six with primary biliary cirrhosis, and 156 with cirrhosis. In the healthy subjects, the Sl was 1.9-5.2% (mean 4.1%). In hepatitis, the mean Sl was 7.1%, and in cirrhosis, 52.9%. The Sl was higher in cirrhotic patients with esophageal varices than in those without (p less than 0.001), and in cirrhotic patients with encephalopathy than in those without (p less than 0.01). For some patients with portal hypertension, portal collateral circulation could be depicted, and images of changes in the portal collateral circulation after vascular anastomosis were seen.

Topics: Administration, Rectal; Adult; Chronic Disease; Collateral Circulation; Esophageal and Gastric Varices; Female; Heart; Hepatitis; Humans; Hypertension, Portal; Liver; Liver Cirrhosis; Liver Cirrhosis, Biliary; Liver Diseases; Methods; Middle Aged; Portal System; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Vena Cava, Inferior

The objective of the present study was to contribute to the development of a noninvasive method for the evaluation of portal circulation using rectally administered radiotracers in dogs. 99mTc absorption was previously checked in rabbits and the present study reports similar results in dogs. Circulation time between the terminal large bowel and the liver (RL-t) and heart (RH-t) was determined by external counting at the hepatic and cardiac level with a large-field computerized gamma camera. In 16 animals studied, average RL-t was 5.2 s and RH-t 8.6 s. In 3 animals with partial binding of the portal vein, RL-t increased to 32, 44 and 34 s. Being noninvasive and harmless, this method could be used to study portal circulation in several physiopathological conditions of the human liver.

Topics: Animals; Dogs; Hypertension, Portal; Portal System; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

Scintisplenoportography was performed on 33 occasions in 28 cirrhotic patients who had bled from esophagogastric varices. In 17 cases scintisplenoportography was carried out after a retroperitoneal distal splenorenal shunt procedure and in the remaining 16 instances in patients without any surgical shunt. In four patients scintisplenoportography was performed before and after a surgical shunt procedure, and in one case, before and after the shunt thrombosed. Gammagraphic patterns and spleen-heart times helped determine which patients did not have a surgical shunt, which had a patent shunt, and which patients had a thrombosed shunt. A patent shunt pattern and a thrombosed shunt pattern have been defined. It is concluded that scintisplenoportography is a useful, reproducible, and safe method to assess the patency of distal splenorenal shunts.

Topics: Esophageal and Gastric Varices; Gastrointestinal Hemorrhage; Humans; Hypertension, Portal; Liver Circulation; Liver Cirrhosis; Portasystemic Shunt, Surgical; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Splenorenal Shunt, Surgical; Technetium; Thrombosis; Time Factors

Quantitative sequential hepatosplenic scintigraphy was performed to determine the arterial and portal components of the total liver circulation in 135 patients (no liver disease in 20, liver cirrhosis and portal ;hypertension in 115). Portal circulation in healthy patients is calculated to be 70.4 +/- 6.2% of the total liver blood flow, whereas patients with portal hypertension showed a clear reduction of portal perfusion to 20.2 +/- 10.9%. Thirteen of 20 patients having portosystemic shunt surgery showed no portal perfusion. This new, noninvasive diagnostic technique yields vital information particularly useful in ;the surgical evaluation of portal hypertension. Other indications are also discussed.

Topics: Angiography; Humans; Hypertension, Portal; Liver; Perfusion; Portal System; Portasystemic Shunt, Surgical; Radionuclide Imaging; Regional Blood Flow; Sodium Pertechnetate Tc 99m; Spleen; Technetium