nitinol and Foreign-Body-Migration

Excisional atherectomy alone or followed by stenting is considered an appropriate treatment strategy for patients with lifestyle-limiting claudication due to obstructive infra-inguinal peripheral arterial disease (Ramaiah et al., J Endovasc Ther 2006;13:592-6021). We present a case of a 69-year-old man with eccentric severely calcified disease of the superficial femoral artery (SFA) treated with excisional atherectomy followed by stenting with an interwoven nitinol stent. The procedure was complicated by extravascular stent migration associated with a contained rupture presenting 30 days after the intervention. The complication was successfully treated with a stent graft. Although rare, pseudoaneurysms have been reported at the site of prior atherectomy; however, this case is the first description of a contained rupture post atherectomy associated with erosion of a nitinol stent into an extra-luminal position. The mechanism and management of this complication are discussed.

Topics: Aged; Alloys; Angioplasty, Balloon; Atherectomy; Blood Vessel Prosthesis Implantation; Femoral Artery; Foreign-Body Migration; Humans; Male; Peripheral Arterial Disease; Prosthesis Design; Radiography; Rupture; Severity of Illness Index; Stents; Time Factors; Treatment Outcome; Ultrasonography, Doppler, Color; Ultrasonography, Interventional; Vascular Calcification; Vascular System Injuries

Endoscopic esophageal stent placement is widely used in the treatment of a variety of benign and malignant esophageal conditions. Self expanding metal stents (SEMS) are associated with significantly reduced stent related mortality and morbidity compared to plastic stents for treatment of esophageal conditions; however they have known complications of stent migration, stent occlusion, tumor ingrowth, stricture formation, reflux, bleeding and perforation amongst others. A rare and infrequently reported complication of SEMS is stent fracture and subsequent migration of the broken pieces. There have only been a handful of published case reports describing this problem. In this report we describe a case of a spontaneously fractured nitinol esophageal SEMS, and review the available literature on the unusual occurrence of SEMS fracture placed for benign or malignant obstruction in the esophagus. SEMS fracture could be a potentially dangerous event and should be considered in a patient having recurrent dysphagia despite successful placement of an esophageal SEMS. It usually requires endoscopic therapy and may unfortunately require surgery for retrieval of a distally migrated fragment. Early recognition and prompt management may be able to prevent further problems.

Topics: Aged; Alloys; Deglutition Disorders; Device Removal; Dilatation; Esophageal Stenosis; Esophagoscopy; Female; Foreign-Body Migration; Humans; Prosthesis Design; Prosthesis Failure; Recurrence; Risk Factors; Stents; Treatment Outcome

Topics: Alloys; Female; Foreign-Body Migration; Humans; Middle Aged; Portal Vein; Portasystemic Shunt, Transjugular Intrahepatic; Postoperative Complications; Radiography; Reoperation; Stents; Time Factors

A 71-year old man with previous thoracic aneurysm endovascular repair and endovascular abdominal aneurysm repair presented with simultaneous type III endoleak from the thoracic components and type Ia endoleak from migration of the abdominal endograft, leading to enlargement of both aneurysms. A custom-made reverse tapered Relay NBS thoracic endograft was used to bridge the thoracic stent grafts. While a low-flow type III endoleak persisted in the immediate postoperative phase, because of incomplete apposition of the new stent graft, further deployment of its nitinol skeleton resulted in resolution of the endoleak at 1-week follow-up. The abdominal aneurysm enlargement was corrected via excision of the central segment of the abdominal endograft, preservation of the distal main body and limbs, and interposition of a short Dacron tube graft.

Topics: Aged; Alloys; Aortic Aneurysm, Abdominal; Aortic Aneurysm, Thoracic; Aortography; Blood Vessel Prosthesis; Blood Vessel Prosthesis Implantation; Computed Tomography Angiography; Endoleak; Endovascular Procedures; Foreign-Body Migration; Humans; Male; Polyethylene Terephthalates; Prosthesis Design; Prosthesis Failure; Stents; Treatment Outcome

To evaluate the technical feasibility, safety, and efficacy of a novel full sense device (FSD) for the treatment of obesity in a porcine model.. The novel FSD comprised a self-expanding metallic esophageal stent connected to a star-shaped nitinol disk. Three types of FSD were used: fully covered (type A), fully covered with barbs (type B), and uncovered with barbs (type C). Nine juvenile pigs were divided into two groups: FSD (n = 6) and control (n = 3). FSD type A was placed in the FSD group. In case of migration, either FSD type B or type C was then randomly placed. Food intake was monitored daily. Weight changes and ghrelin hormone levels were monitored weekly for 12 weeks.. FSD placement was technically successful in all pigs. All FSDs except one migrated to the stomach within 1 week after placement. The pig in which the FSD was retained showed decreased food intake in the first week after FSD placement, and there was a difference in the final weight between the FSD pig and control pigs. The percentage of weight gain was 116.6% in the control group and 105.3% in the FSD pig.. FSD placement under fluoroscopic and endoscopic guidance is technically feasible and safe in a porcine model. The uncovered FSD appears to decrease food intake and reduce the rate of weight gain. However, the high FSD migration rate is not encouraging.

Topics: Alloys; Animals; Eating; Endoscopy; Feasibility Studies; Fluoroscopy; Foreign-Body Migration; Obesity; Prosthesis Design; Prosthesis Failure; Prosthesis Implantation; Random Allocation; Satiation; Stents; Stomach; Swine; Treatment Outcome; Weight Gain

Topics: Aged; Alloys; Aortic Aneurysm, Abdominal; Aortography; Blood Vessel Prosthesis; Blood Vessel Prosthesis Implantation; Endovascular Procedures; Female; Foreign-Body Migration; Humans; Prosthesis Design; Prosthesis Failure; Stents; Time Factors; Treatment Outcome; Ultrasonography, Doppler, Duplex

The use of Endobronchial coils are a relatively new brochoscopic technique for lung volume reduction. They appear to be safe and effective in improving quality of life, reducing morbidity and mortality related to the primary disease, while avoiding the many risks of morbidity and mortality associated with surgery. Nevertheless, some complications, such as pneumothorax, are relatively common in the periprocedural period. We describe a case of pneumothorax that occurred several days after brochoscopic technique for lung volume reduction due to direct perforation of the visceral pleura by a coil. The patient presented with a large pneumothorax associated with significant air leak, requiring surgical intervention. Exploration of the chest cavity showed a pleural tear caused by a coil. To our knowledge, this is an adverse event that has never been described before, suggesting the possible migration of the coil from the original position.

Topics: Alloys; Bronchoscopy; Female; Foreign-Body Migration; Humans; Middle Aged; Pneumonectomy; Pneumothorax

We report a preliminary experience about endovascular aortic repair (EVAR) of infrarenal abdominal aortic aneurysm (iAAA) with severe proximal aortic neck angulation (NA) using the Aorfix™ stent graft.. Data of consecutive patients with iAAA with severe proximal NA submitted to endovascular repair between September 2012 and December 2014 in 2 Italian centers of Vascular and Endovascular Surgery were retrospectively reviewed, and outcomes were analyzed using the software JMP 5.1.2.. A total of 26 patients were treated. Median proximal NA was 87.5° (range 68-108°), and 3 patients were treated outside the instruction for use of Aorfix because of a proximal NA > 90°. Eleven patients (42.3%) had severe iliac tortuosity. The primary success rate was 92.3%, as 2 patients required intraoperative correction of a type Ia endoleak. Within 30 days, a right limb occlusion was successfully resolved with endovascular recanalization. The median follow-up period was 14 months (range 1-48 months): 1 patient died for neoplasm and 1 patient presented a type II endoleak from lumbar arteries at 3 months, which is still under surveillance. No other complications were reported during the follow-up period.. Preliminary results with the Aorfix stent graft seemed to be promising in the aim of reducing endoleak and migration rates in presence of iAAA with severe proximal aortic NA.

Topics: Aged; Alloys; Aortic Aneurysm, Abdominal; Aortography; Blood Vessel Prosthesis; Blood Vessel Prosthesis Implantation; Computed Tomography Angiography; Endoleak; Endovascular Procedures; Female; Foreign-Body Migration; Humans; Italy; Male; Preliminary Data; Prosthesis Design; Retrospective Studies; Stents; Time Factors; Treatment Outcome

Lower extremity ischemia following deployment of a vascular closure device for access site closure after a transfemoral endovascular procedure rarely occurs. A 68-year-old woman diagnosed with subarachnoid hemorrhage due to a ruptured anterior communicating aneurysm was treated by endovascular coil embolization. The StarClose SE device was deployed for right femoral arteriotomy closure. After 2 days, critical ischemia occurred on her right lower leg due to total occlusion of the popliteo-tibial artery. Emergent surgical embolectomy was performed and the nitinol clip of the StarClose device was captured in the lumen of the tibioperoneal trunk. Although StarClose is an extravascular closure system, intravascular deployment, distal migration, and resultant critical limb ischemia can occur.

Topics: Aged; Alloys; Arterial Occlusive Diseases; Embolectomy; Embolization, Therapeutic; Female; Femoral Artery; Foreign-Body Migration; Hemostatic Techniques; Humans; Ischemia; Lower Extremity; Popliteal Artery; Surgical Instruments; Tibial Arteries; Treatment Outcome

To evaluate the long-term clinical outcomes and the negative predictors after the deployment of double-layered stents in malignant esophageal strictures.. This is a single-center study of patients who received a double-layered covered stent for the palliation of dysphagia due to malignant esophageal strictures in a 3-year period. 56 patients fulfilled the inclusion criteria. The study's primary end points were technical success, dysphagia improvement, stent migration, and complication rates; secondary end points were the stent's primary patency and overall survival. Cox regression analysis was used to adjust for confounding variables and to identify predictors of survival outcomes.. Technical success was 95%. Median dysphagia score improved significantly after stenting (p < 0.0001). Stent migration rate was 7.1% and occurred exclusively in the group of patients who received chemoradiotherapy (p < 0.01). The median stent patency was 87 days (range 5-444 days). Dysphagia reoccurred in 39.3% and was successfully managed with restenting in 98.2%. The median survival was 127 days (range 15-1480 days). Chemoradiotherapy and baseline histology did not influence survival outcomes. Survival was adversely affected by metastases (p = 0.005) and poor oral intake (p = 0.048). Patient survival was improved by repeat stenting in case of tissue overgrowth (p = 0.06).. The device is safe and effective for the treatment of patients with dysphagia due to esophageal cancer. Migration rate is zero for patients who do not receive chemoradiotherapy. Reintervention when required is a positive survival predictor.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Chemoradiotherapy; Deglutition Disorders; Esophageal Neoplasms; Female; Fluoroscopy; Foreign-Body Migration; Humans; Male; Middle Aged; Palliative Care; Postoperative Complications; Predictive Value of Tests; Prosthesis Design; Recurrence; Retreatment; Retrospective Studies; Risk Factors; Stents; Survival Rate; Treatment Outcome

Topics: Aged; Alloys; Angiography, Digital Subtraction; Angioplasty, Balloon; Aorta, Abdominal; Constriction, Pathologic; Device Removal; Foreign-Body Migration; Humans; Iliac Artery; Male; Middle Aged; Peripheral Arterial Disease; Prosthesis Design; Stents; Treatment Outcome; Vascular System Injuries

Topics: Alloys; Cholestasis; Colonic Diseases; Constriction, Pathologic; Duodenal Obstruction; Equipment Design; Esophageal Stenosis; Foreign-Body Migration; Humans; Intestinal Atresia; Postoperative Complications; Stents

To describe early clinical experience with the amplatzer ductal occluder II additional sizes (ADO II AS) for percutaneous arterial duct occlusion in infants and small children.. Pre-, intra- and postprocedural data analysis of all patients undergoing arterial duct occlusion with the ADO II AS from three tertiary referral centers.. 17 patients (10 female) with a median age of 6 months (range 1.0-48.1 months) and a median weight of 5.7 kg (range 1.7-17.4 kg) underwent attempted transcatheter ductal closure with the ADO II AS. Retrograde arterial approach was used in eight patients with transvenous femoral approach used in nine. The mean minimal ductal diameter was 2.2 ± 0.7 mm with mean ductal length of 6.8 ± 1.7 mm. Device sizes used were 5/6 (n = 5), 3/4 (n = 4), 4/4 (n = 3), 4/6 (n = 3), and 5/4 (n = 2) with four French delivery sheaths used in all cases. The median fluoroscopy time was 5.7 ± 1.8 min. Two patients underwent delivery under exclusive echocardiography guidance. Complete ductal occlusion was achieved by the end of the procedure in 13 patients. Device embolization to the left pulmonary artery occurred in one patient with successful surgical removal and ligation of the arterial duct. Three patients required device resizing following deployment of the initial device. Complete ductal occlusion without aortic arch or left pulmonary artery stenosis has been identified in all 16 remaining patients on transthoracic echocardiographic follow-up at median of 4.2 months.. The new amplatzer ductal occluder II AS achieves excellent ductal closure rates through low profile delivery systems in small infants and children with variable ductal anatomy.

Topics: Age Factors; Alloys; Cardiac Catheterization; Child, Preschool; Device Removal; Ductus Arteriosus, Patent; England; Female; Foreign-Body Migration; Humans; Infant; Ireland; Ligation; Male; Prosthesis Design; Pulmonary Artery; Radiography, Interventional; Retrospective Studies; Tertiary Care Centers; Time Factors; Treatment Outcome; Ultrasonography, Interventional

Patent ducti arteriosi (PDAs) are more frequent and larger at high altitude than at sea level. A novel PDA closure device, the Nitocclud PDA-R, is designed specifically for both large and medium size PDAs. The initial clinical experience with a new nitinol-based device in high altitude patients with large PDAs is described.. The Nitocclud PDA-R is a self-expandable, self-centering, repositionable occluder made of one nitinol wire without use of welding. It contains several polyester membranes, is delivered with a central guide wire and is released by retraction of the central wire into the delivery catheter. The efficacy of this device was evaluated at several high altitude centers.. Fifty-one patients without other congenital cardiac defects underwent transcatheter closure of PDA. Complete occlusion of the PDA was achieved in 98% of the patients. Nearly 49% of the patients had no shunt immediately after device implantation. Echocardiography revealed a complete closure rate by Doppler interrogation of 69% after 24 hr, 96% after 6 months, and 98% after 1 year. In two cases, device embolization was observed after release, and in both cases the device was easily retrieved with standard interventional techniques. There have been no episodes of delayed device migration, endocarditis, hemolysis, wire fracture, device disruption, or death.. The Nitocclud PDA-R device is safe and effective and can easily close very large PDAs. This device has a high rate of complete occlusion within 1 year and is easily retrieved if embolized.

Topics: Adolescent; Adult; Alloys; Altitude; Argentina; Bolivia; Cardiac Catheterization; Child; Child, Preschool; Device Removal; Ductus Arteriosus, Patent; Echocardiography, Doppler, Color; Equipment Design; Female; Foreign-Body Migration; Hemodynamics; Humans; Infant; Male; Membranes, Artificial; Polyesters; Prospective Studies; Therapeutics; Time Factors; Young Adult

Fully covered esophageal self-expandable metallic stents (SEMS) often are used for palliation of malignant dysphagia. However, experience and data on these stents are still limited. The purpose of this multicenter study was to evaluate the efficacy and safety of fully covered nitinol SEMS in patients with malignant dysphagia.. 37 patients underwent placement of a SEMS during a 3 year period. Five patients underwent SEMS placement as a bridge to surgery: one for tracheoesophageal fistula in the setting of squamous cell carcinoma of the esophagus, one for perforation in setting of esophageal adenocarcinoma, 27 for unresectable esophageal cancer (16 adenocarcinoma, 11 squamous cell carcinoma), two for lung cancer, and one for breast-cancer-related esophageal strictures.. SEMS placement was successful in all 37 patients. Immediate complications after stent deployment included chest pain (n = 6), severe heartburn (n = 1), and upper gastrointestinal bleeding requiring SEMS revision (n = 1). Dysphagia scores improved significantly from 3.2 ± 0.4 before stent placement to 1.4 ± 1.0 at 1 month (P < 0.0001), 1.1 ± 1.2 (P < 0.0001) at 3 months, and 1.3 ± 1.4 (P = 0.0018) at 6 months. The stent was removed in 11 patients (30%) for the following indications: resolution of stricture (n = 3), stent malfunction (n = 5), and stent migration (n = 3). After stent removal, three patients were restented, three underwent dilation, and two underwent PEG placement. Mean survival for the 37 patients after stent placement was 146.3 ± 143.6 (range, 13-680) days.. Our study suggests that fully covered SEMS placement improve dysphagia scores in patients with malignant strictures, particularly in the unresectable population. Further technical improvements in design to minimize long-term malfunction and migration are required.

Topics: Aged; Alloys; Deglutition Disorders; Device Removal; Esophageal Neoplasms; Esophageal Stenosis; Female; Fluoroscopy; Foreign-Body Migration; Humans; Male; Middle Aged; Prosthesis Failure; Radiography, Interventional; Stents; Treatment Outcome

Median sternotomy is the most common method of access to the heart and great vessels in cardiac surgical procedures. However, particularly in obese and diabetic patients, complications such as dehiscence, osteomyelitis, mediastinitis and superficial wound infection or fistula formation may be encountered. To overcome these complications, some alternative surgical techniques and surgical equipment are designed for sternal closure. 'Nitinol thermoreactive clips' is one of them. In this study, we report a patient with detachment of thermoreactive clips from sternum in the late postoperative period due to wrong measurement of distance between intercostal spaces.

Topics: Adult; Alloys; Equipment Design; Equipment Failure; Foreign-Body Migration; Humans; Male; Medical Errors; Radiography; Reoperation; Sternotomy; Sternum; Surgical Instruments; Treatment Outcome

The purpose of this study was to evaluate the clinical effectiveness of polytetrafluoroethylene (PTFE)-covered retrievable expandable nitinol stents in patients with malignant esophageal strictures and to identify prognostic factors associated with clinical outcomes.. From 2001 to 2010, 320 PTFE-covered stents were placed in 270 patients. Technical and clinical success, complications, survival, and stent patency were measures of clinical effectiveness. The relationships among complications and age, sex, stricture location, stricture length, chemotherapy alone, chemoradiotherapy, and malignancy source were examined. Independent prognostic factors of overall survival and stent patency were identified.. Stent placement and removal were technically successful and tolerated without procedural complications, and 98% of patients achieved clinical success. The complication rate was 30%. Two removed stents exhibited covering membrane separation. Chemotherapy was associated with increased stent migration (p = 0.002). Stricture location and chemoradiotherapy were associated with esophagorespiratory fistula development (p = 0.033 and p < 0.001, respectively). Median and mean survival periods were 114 days (95% CI, 102-126 days) and 166 days (138-193 days). Chemotherapy and chemoradiotherapy were independent prognostic factors for survival (p = 0.050 and p = 0.032, respectively). The median and mean stent patency periods were 60 days (41-79 days) and 90 days (71-108 days). Chemoradiotherapy was the only independent prognostic factor for stent patency (p = 0.012).. The PTFE-covered stents were clinically effective. Membrane degradation was not evident, although 0.7% of the patients experienced covering membrane separation. Chemotherapy was associated with increased migration and prolonged survival. Chemoradiotherapy was associated with increased esophagorespiratory fistula formation and decreased stent patency.

Topics: Alloys; Coated Materials, Biocompatible; Combined Modality Therapy; Device Removal; Esophageal Neoplasms; Esophageal Stenosis; Female; Fluoroscopy; Foreign-Body Migration; Humans; Male; Middle Aged; Polytetrafluoroethylene; Prognosis; Proportional Hazards Models; Radiography, Interventional; Retrospective Studies; Risk Factors; Stents; Survival Rate; Treatment Outcome

Self-expandable metallic stents (SEMS) of varying designs and materials have been developed to reduce complications, but few comparative data are available with regard to the type of stent and the stent manufacturer. We analyzed the success rates and complication rates, according to stent type (uncovered vs. covered stent) and individual stent manufacturer, in malignant colorectal obstruction.. From November 2001 to August 2008, 103 patients were retrospectively included in this study: four types of uncovered stents in 73 patients and two types of covered stents in 30 patients. The SEMS was inserted into the obstructive site by using the through-the-scope method.. Technical and clinical success rates were not different between stent type or among stent manufacturers: 100 and 100% (p = ns) and 100 and 96.6% (p > 0.05), respectively, in uncovered and covered stents. Stent occlusion and migration rates were 12.3 and 3.3% (p = 0.274) and 13.7 and 16.7% (p = 0.761), respectively, in uncovered and covered stents, and 11.1, 5, and 9% (p = 0.761) and 25.9, 15, and 0% (p = 0.037) in Wallstent, Niti-S, and Bonastent uncovered stents, respectively.. The placement of SEMS is an effective and safe treatment for patients with malignant colorectal obstruction. Although minor differences in outcome were detected according to the type and the manufacturer of the stents, no statistically significant difference was observed, except in stent migration among the stent manufacturer.

Topics: Adenocarcinoma; Aged; Aged, 80 and over; Alloys; Carcinoma; Chromium Alloys; Coated Materials, Biocompatible; Cobalt; Colonic Diseases; Colonic Neoplasms; Colonoscopy; Equipment Design; Female; Fluoroscopy; Foreign-Body Migration; Humans; Intestinal Obstruction; Male; Middle Aged; Palliative Care; Pancreatic Neoplasms; Radiography, Interventional; Rectal Diseases; Stents; Stomach Neoplasms; Treatment Outcome; Uterine Cervical Neoplasms

To report the use of a newly constructed, covered, retrievable, expandable nitinol stent with barbs to overcome the problem of stent migration associated with conventional covered prostatic expandable stents and to evaluate prospectively the technical feasibility and clinical effectiveness of the stents in patients with benign prostatic hyperplasia (BPH).. A covered retrievable expandable nitinol stent with four barbs was placed with use of an 18-F stent delivery system in seven consecutive patients with symptomatic BPH who had high operative risks. Age range of patients was 62-83 years (mean 74 years). In cases in which the stent migrated, it was replaced with a stent with eight barbs. The stents were routinely removed 4 months after placement using a 21-F stent removal set.. Stent placement was technically successful and well tolerated in six of the seven patients. The remaining patient needed a second stent placement after removal of the first stent. The stent with four barbs migrated into the urinary bladder in four patients (57%); three of these patients received a second stent with eight barbs with good results, and the fourth patient did not need further treatment because his symptoms improved. Routine removal of the stent 4 months after placement was performed in three of the seven patients with good results.. Retrievable stents with eight barbs seem to overcome the problem of stent migration associated with conventional prostatic expandable stents. Preliminary results suggest that stents with barbs are both feasible and effective in patients with BPH.

Topics: Aged; Aged, 80 and over; Alloys; Catheterization; Device Removal; Feasibility Studies; Foreign-Body Migration; Humans; Male; Pilot Projects; Prospective Studies; Prostatic Hyperplasia; Prosthesis Design; Radiography, Interventional; Republic of Korea; Stents; Time Factors; Treatment Outcome; Ureteroscopy

The purpose of this study was to evaluate the safety and effectiveness of a barbed silicone-covered retrievable expandable nitinol stent in preventing stent migration in patients with tracheal strictures or fistulas.. Under fluoroscopic guidance, barbed silicone-covered retrievable expandable nitinol stents were placed in 15 patients with tracheal strictures, two patients with fistulas, two patients with combined strictures and fistulas, and one patient with variable extrathoracic airway obstruction. The three pairs of barbs were attached to the external stent surface at the middle of the stent at equal intervals. Technical success, improvement in respiratory status, complications, and related interventions were evaluated.. The technical success rate was 100%, and respiratory status improved or the fistula closed in all 20 patients. Complications included sputum retention (three patients), tumor overgrowth (three patients), pain (one patient), and granulation tissue formation (one patient). No stent migration occurred, even in the three patients without fixed strictures. Four stents subsequently were removed because of complications, and one stent was removed because the patient's condition improved. Stent removal was not difficult and was uneventful. The silicone membranes and barbs of the removed stents were intact.. Use of a barbed silicone-covered retrievable expandable nitinol stent relieves dyspnea and facilitates fistula closure in patients with benign or malignant tracheal strictures or fistulas. The barbed design of the stent is important in preventing migration.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Coated Materials, Biocompatible; Device Removal; Female; Fluoroscopy; Foreign-Body Migration; Humans; Male; Middle Aged; Radiography, Interventional; Silicones; Stents; Tomography, X-Ray Computed; Tracheal Stenosis; Tracheoesophageal Fistula; Treatment Outcome

To assess short-term survival after transcatheter mitral valve replacement using a unique mitral valved stent design and anchoring system.. The new nitinol self-expandable valved stent houses a trileaflet glutaraldehyde-preserved bioprosthesis and contains atrial and ventricular fixation systems. Eight pigs underwent transesophageal echocardiogram-guided transapical mitral valved stent implantation through a lower mini-sternotomy. Intracardiac pressure gradients were estimated by transesophageal echocardiogram.. The mean mitral annulus size was 24.6 +/- 1.4 mm, and the valved stent size was 26.0 +/- 2.6 mm. The average mean transvalvular gradient across the valved stent immediately after deployment, at 6 hours, and after 1 week remained low. The gradient across the neighboring left ventricular outflow tract was not affected. Average animal survival was 7.3 days (8 hours to 29 days). Animals that died before 1 week (n = 4) were found at necropsy to have valved stent malpositioning. Animals that survived 1 week or more had accurate deployment and only trace post-deployment paravalvular leak. The causes of death in this latter group were endocarditis (n = 1), failure of atrial fixation (n = 2), and failure of ventricular fixation (n = 1). There was no valved stent embolization in any of the animals.. Adequate function and effective anchoring of the new mitral valved stent allowed for short-term animal survival after transapical mitral valved stent implantation.

Topics: Alloys; Animals; Bioprosthesis; Cardiac Catheterization; Echocardiography, Transesophageal; Fixatives; Foreign-Body Migration; Glutaral; Heart Valve Prosthesis; Heart Valve Prosthesis Implantation; Mitral Valve; Prosthesis Design; Prosthesis Failure; Sternotomy; Swine; Time Factors; Ultrasonography, Interventional

Topics: Aged; Alloys; Catheterization; Coated Materials, Biocompatible; Colon; Device Removal; Equipment Failure Analysis; Esophageal Stenosis; Female; Foreign-Body Migration; Humans; Radiography; Recurrence; Silicone Elastomers; Stents

Curative resection is often contraindicated in patients with airway obstruction by aggressive thyroid disease.. To evaluate the safety and clinical effectiveness of covered retrievable self-expandable nitinol stents placed in patients with airway obstruction caused by benign or malignant thyroid disease.. From 1996 to 2009, covered retrievable self-expandable nitinol stents were placed in nine symptomatic patients with malignant (n=7) or benign (n=2) thyroid disease. Improvement in patient respiratory status, complications and their management, and survival data were evaluated. Stents were removed if stent-related complications occurred or the stents were no longer necessary.. A total of 11 stents were successfully placed without procedure-related complications. Improvement of more than one dyspnea grade was seen in eight of nine patients (89%), while the ninth patient underwent intubation due to upper airway swelling. Stent migration, sputum retention, and tumor overgrowth occurred in 27.3% (n=3), 9.1% (n=1), and 9.1% (n=1) of the stents, respectively. A total of six stents were successfully removed because of stent-related complications (n=4) or after total thyroidectomy (n=2). In two patients with benign thyroid goiters, a stable airway was maintained until total thyroidectomy.. Placement of covered retrievable self-expandable nitinol stents was safe and effective in patients with airway obstruction caused by benign or malignant thyroid disease. Stent retrievability was very useful in cases of stent-related complications. In patients with benign thyroid disease, stent placement can serve as an effective bridge to surgery.

Topics: Adult; Aged; Alloys; Bronchoscopy; Coated Materials, Biocompatible; Device Removal; Female; Foreign-Body Migration; Humans; Male; Middle Aged; Stents; Thyroid Diseases; Thyroid Neoplasms; Thyroidectomy; Tracheal Stenosis; Treatment Outcome

To find out whether a newly designed big cup nitinol stent is suitable for treatment of patients with gastric outlet obstruction resulting from gastric cancer.. The new stent is composed of a proximal big cup segment (20 mm in length and 48-55 mm in diameter), a middle part (60 mm in length and 20 mm in diameter) covered by a polyethylene membrane and a distal sphericity (20 mm in length and 28 mm in diameter). Half of the proximal big cup segment is also covered by a polyethylene membrane, which is adjacent to the middle part of the stent. The stent is preloaded in a 6.0-mm-diameter introducer system. Thirteen patients with gastric outlet obstruction resulting from gastric cancer received the new stents under endoscopic and fluoroscopic guidance.. Technical success was achieved in 12 of 13 (92.3%) patients. Among the 12 patients in whom endoscopic stent was placed successfully, the clinical success rate was 91.7% during a follow-up of average 6.5 mo. During the first month follow-up, the migration rate was 0%, recurrent obstruction 0% and gastric bleeding 8.3%. During the follow-up between 2-12 mo, no migration, recurrent obstruction and gastric bleeding occurred.. The proximal big cup segment seems to be effective and promising for technical efficacy, clinical outcome, and preventing migration and tumor ingrowth and increasing the emptying rate of sinus ventriculi.

Topics: Aged; Aged, 80 and over; Alloys; Endoscopy, Gastrointestinal; Female; Follow-Up Studies; Foreign-Body Migration; Gastric Outlet Obstruction; Humans; Male; Neoplasm Invasiveness; Polyethylene; Prevalence; Stents; Stomach Neoplasms; Treatment Outcome

The potential role of AERO tracheobronchial covered stents in the management of recurrent postinfectious strictures of the bronchus intermedius was studied in three lung transplant recipients. Six devices were inserted. Five of the stents migrated immediately on placement. Buildup of thick mucus was observed in all stents remaining in the airway for longer than 1 week. Strictures recurred in all patients 1, 3, and 5 months after stent deployment. Attempts at stent retrieval were successful for three of five devices. The use of AERO stents may not offer a therapeutic advantage versus balloon dilation of bronchus intermedius strictures in lung transplant recipients.

Topics: Adult; Aged; Airway Obstruction; Alloys; Bronchial Diseases; Bronchoscopy; Catheterization; Coated Materials, Biocompatible; Constriction, Pathologic; Female; Foreign-Body Migration; Humans; Lung Transplantation; Male; Middle Aged; Polyurethanes; Prosthesis Design; Recurrence; Stents; Time Factors; Treatment Outcome

To assess the efficacy and safety of covered retrievable nitinol stents in oesophageal cancer patients with airway involvement.. Under fluoroscopic guidance, covered retrievable nitinol airway stents were placed in 23 oesophageal cancer patients with airway stricture and/or oesophagorespiratory fistula (ERF) over a long period of 12 years. Six patients only had aspiration by ERF and three patients had both airway stricture and asymptomatic ERF. Technical aspects, dyspnoea improvement, and/or resolution of ERF symptoms, complications, reinterventions, and survival data were evaluated.. A total of 27 airway stents (14 tracheal, 11 bronchial, and two hinged) were placed successfully in 23 patients with airway stricture or ERF. Dyspnoea score decreased significantly after stent placement (p<0.001). ERF were sealed off in all nine patients. Complications included stent migration or expectoration (n=4), haemoptysis (n=2), sputum retention (n=7), and tumour overgrowth (n=1). All three migrated stents were easily removed. Twenty-one patients died, with the median survival period of 76 days (range 2-197 days).. Placement of covered retrievable expandable nitinol stents was safe and effective for the palliative treatment of airway strictures and/or ERF, with a reasonable range of complications, in patients with advanced oesophageal cancer.

Topics: Adult; Aged; Airway Obstruction; Alloys; Bronchi; Bronchography; Device Removal; Epidemiologic Methods; Esophageal Fistula; Esophageal Neoplasms; Female; Fluoroscopy; Foreign-Body Migration; Humans; Male; Middle Aged; Neoplasm Invasiveness; Palliative Care; Radiography, Interventional; Respiratory Tract Fistula; Stents; Tracheal Stenosis; Treatment Outcome

Diagnostic cardiac catheterizations are predominantly performed using access through the femoral artery. To improve patient comfort and early mobilization, a number of percutaneous closure devices have been developed. One such device using the nitinol clip was developed by Abbott Vascular Devices and was approved for use on the basis of the results of the Clip Closure In Percutaneous Procedures (CLIP) study. The safety of repuncture through a previously deployed device has not been established in humans. We present the case of a patient who had an arterial line placed for post-operative monitoring after cardiac surgery at the site of a previous arteriotomy closed with the Starclose device. The catheter traversed through the central portion, tethered to the periphery of the ninitol clip, and required surgery for extraction.

Topics: Aged; Alloys; Cardiac Catheterization; Cardiac Surgical Procedures; Catheterization, Peripheral; Device Removal; Equipment Design; Femoral Artery; Foreign-Body Migration; Hemorrhage; Hemostatic Techniques; Humans; Male; Postoperative Care; Punctures; Radiography; Treatment Outcome; Vascular Surgical Procedures

Topics: Alloys; Cardiac Catheterization; Catheterization, Peripheral; Equipment Design; Femoral Artery; Foreign-Body Migration; Hemorrhage; Hemostatic Techniques; Humans; Punctures

The endoscopic placement of metallic stents for palliation of malignant obstruction of the GI or biliary tract is an established practice and as such is often applied. Use of these stents, however, has its problems. Stent migration may cause obstruction of the bowel lumen. Migration of a biliary stent into the contralateral duodenal wall may cause difficulty in gaining access to the biliary tract, as will the placement of a duodenal stent across the ampulla.. We report on 6 patients in whom trimming of the metallic nitinol stent was performed.. Single-center, retrospective case series.. Secondary referral center.. Of 6 patients included, 2 patients each had an uncovered duodenal stent, 2 had an uncovered biliary stent each, 1 had an uncovered colorectal stent, and 1 had a covered gastroduodenal stent.. Under direct endoscopic vision, an argon plasma beam was used to cut self-expandable metallic stents, as appropriate.. The main objective was relief of the obstruction to the bowel lumen or bile duct, facilitating successful passage of an endoscope or biliary canulation, respectively.. In all 5 patients with uncovered metallic stents, we were able to re-establish access to the obstructed bowel lumen or the biliary tree, as indicated. An attempt to tailor the length of a covered metallic gastroduodenal stent failed. No complications were observed and no hemorrhage or perforation occurred.. The study was limited by retrospective design and small sample size.. The endoscopic cutting and tailoring of an uncovered metallic prosthesis, by means of an argon plasma beam, is feasible, effective, and safe. Trimming of covered stents is not advocated.

Topics: Adenocarcinoma; Aged; Alloys; Argon; Biliary Tract Neoplasms; Device Removal; Electrosurgery; Endoscopy, Gastrointestinal; Female; Foreign-Body Migration; Humans; Intestinal Obstruction; Male; Middle Aged; Pancreatic Neoplasms; Stents

This brief report describes an unusual hybrid approach complication of aortic arch disease. An acute stent kinking in the first post-operative day promoted ventricular fibrillation and death. Adequate oversizing was achieved and intraoperative angiogram showed no proximal or distal leaks. Unfavorable outcomes are highly under-reported and describing complications are a key instrument to improve this technique.

Topics: Alloys; Anastomosis, Surgical; Aortic Aneurysm, Thoracic; Blood Vessel Prosthesis; Blood Vessel Prosthesis Implantation; Fatal Outcome; Foreign-Body Migration; Humans; Male; Middle Aged; Polyethylene Terephthalates; Prosthesis Design; Prosthesis Failure; Stents; Sternum; Time Factors; Tomography, X-Ray Computed; Treatment Outcome; Ventricular Fibrillation

Prostatic urethral stents are effective in relieving obstructions caused by benign prostatic hyperplasia (BPH). However, migration of these stents occurs frequently.. To evaluate the efficacy of a flared stent for decreasing the migration rate in comparison with a straight stent in a canine prostatic urethral model.. The flared stent (15 mm in diameter and 20 mm in length) was flared up to 19 mm at both ends to prevent migration. A straight stent with the same size was straight without flaring. Both stents were made of a nitinol wire filament and covered with an expanded polytetrafluoroethylene (ePTFE) membrane. The flared stent was inserted in the prostatic urethra of 10 dogs (group 1) and the straight stent in the prostatic urethra of 12 dogs (group 2). Follow-up retrograde urethrography (RUG) was performed 1, 4, and 8 weeks after stent placement. Fisher's exact test was used to compare the migration rate between the two groups. When stent migration occurred during the follow-up period, the same type of stent was inserted again.. Three of 10 (30.0%) flared stents migrated into the urinary bladder between 1 week and 4 weeks after placement. Seven of 12 (58.3%) straight stents migrated into the urinary bladder 1 (n = 3), 4 (n = 1), and 8 (n = 3) weeks following placement. The flared stent group showed lower migration rate than the straight stent group, but the migration rate did not reach statistical significance (P = 0.231). After the second stent placement, one of three (33.3%) flared stents migrated again after 4 weeks and two of seven straight stents (28.6%) after 1 week.. Although the migration rate was not statistically significant, the flaring of the stent seemed to reduce the migration rate in comparison with straight stents in a canine prostatic urethral model. However, the migration rate of the flared stent was still high, and further developments are required to decrease migration rate.

Topics: Alloys; Animals; Coated Materials, Biocompatible; Disease Models, Animal; Dogs; Equipment Design; Follow-Up Studies; Foreign-Body Migration; Male; Polytetrafluoroethylene; Prostate; Radiography; Stents; Treatment Outcome; Urethra; Urinary Bladder

Migration, distal malposition or fracture of self-expanding metallic biliary or esophageal stents rarely occur but may lead to stent dysfunction, mucosal trauma secondary to impaction or friction on the digestive wall. We report our experience of using argon plasma to endoscopically cut three metallic biliary and esophageal self-expanding stents to restore permeability or to treat impaction of the stent after migration, malposition or fracture.

Topics: Aged; Aged, 80 and over; Alloys; Deglutition Disorders; Duodenal Ulcer; Duodenoscopy; Endoscopes, Gastrointestinal; Esophagus; Foreign-Body Migration; Gastroscopy; Hepatic Duct, Common; Humans; Lasers, Gas; Male; Prosthesis Design; Prosthesis Failure; Silicones; Stents; Treatment Outcome

Topics: Alloys; Angioplasty, Balloon; Arterial Occlusive Diseases; Device Removal; Equipment Design; Femoral Artery; Foreign-Body Migration; Foreign-Body Reaction; Giant Cell Arteritis; Hemorrhage; Hemostatic Techniques; Humans; Patient Selection; Pressure; Punctures; Risk Factors; Skin Diseases; Ultrasonography

We report the first case of a transcutaneous migration of a vascular clip closure device 10 weeks after placement during femoral artery puncture for percutaneous transluminal angioplasty. We postulate focal inflammatory vascular wall changes as the predisposing factor in this patient with giant cell arteritis.

Topics: Aged; Alloys; Angioplasty, Balloon; Arterial Occlusive Diseases; Device Removal; Equipment Design; Female; Femoral Artery; Foreign-Body Migration; Foreign-Body Reaction; Giant Cell Arteritis; Hemorrhage; Hemostatic Techniques; Humans; Punctures; Risk Factors; Skin Diseases; Ultrasonography

To evaluate the feasibility and accuracy of Roentgen stereophotogrammetric analysis (RSA) versus computed tomography (CT) for detecting stent-graft migration in an in vitro pulsatile circulation model and to study the feasibility of a nitinol endovascular clip (NEC) as an aortic wall reference marker for RSA.. An aortic model with stent-graft was constructed and connected to an artificial circulation with a physiological flow and pressure profile. Tantalum markers and NECs were used as aortic reference markers for RSA analysis. Stent-graft migrations were measured during pulsatile circulation with RSA and CT. CT images acquired with 64 x 0.5-mm beam collimation were analyzed with Vitrea postprocessing software using a standard clinical protocol and central lumen line reconstruction. RSA in the model with the circulation switched off was used as the reference standard to determine stent-graft migration. The measurement errors of RSA and CT were determined during pulsatile circulation.. The mean measurement error +/- standard deviation (maximum) of RSA during pulsatile circulation using the tantalum markers was -0.5+/-0.16 (0.7) mm. Using the NEC, the mean (maximum) measurement error was -0.4+/-0.25 (1.1) mm. The mean (maximum) measurement error of CT was -1.1+/-1.17 (2.8) mm.. RSA is an accurate and feasible tool to measure stent-graft migration in a pulsatile environment. Migration measurement with RSA was more accurate than CT in this experimental setup. The nitinol clip tested in this study is potentially feasible as an aortic reference marker in patients after endovascular repair.

Topics: Alloys; Animals; Aorta, Thoracic; Aortography; Blood Pressure; Blood Vessel Prosthesis Implantation; Equipment Design; Feasibility Studies; Foreign-Body Migration; Humans; Imaging, Three-Dimensional; Models, Cardiovascular; Photogrammetry; Pulsatile Flow; Radiographic Image Interpretation, Computer-Assisted; Radiography; Reference Values; Reproducibility of Results; Stents; Surgical Instruments; Swine; Tantalum; Tomography, X-Ray Computed

Nitinol stents have been used in the treatment of benign tracheal stenosis. A retrospective review of five patients treated at Stobhill Hospital over the last six and a half years is presented. Age at presentation ranged from 17 to 76 years. The minimum follow-up period was 23 months and the maximum was 78 months. All our patients were successfully decannulated, with none requiring recannulation. Four patients developed granulation tissue related to the stent at intervals ranging from three weeks to 41 months post stenting. Topical mitomycin C application has been useful after resection of granulations using the carbon dioxide (CO2) laser. Stent migration occurred in one patient three weeks after insertion. Nitinol stents are easy to insert and effective in the treatment of tracheal stenosis, but can have associated morbidity. Their use should be considered carefully, as insertion should be regarded as permanent. Publications reporting experience and outcome with the use of Nitinol stents in the trachea are reviewed.

Topics: Administration, Topical; Adolescent; Adult; Aged; Alloys; Antibiotics, Antineoplastic; Cartilage Diseases; Female; Foreign-Body Migration; Granuloma, Foreign-Body; Humans; Laser Therapy; Male; Middle Aged; Mitomycin; Patient Satisfaction; Retrospective Studies; Stents; Tracheal Diseases; Tracheal Stenosis; Treatment Outcome

Topics: Alloys; Equipment Safety; Foreign-Body Migration; Hematuria; Humans; Male; Prostatic Hyperplasia; Prostatic Neoplasms; Prosthesis Design; Stents; Urinary Incontinence; Urination

To assess the efficacy, safety, and durability of the bell-shaped nitinol prostatic stent in the treatment of moderate to severe lower urinary tract symptoms caused by benign prostatic enlargement in otherwise healthy patients.. Stents were inserted in an outpatient setting under local anaesthesia. Assessments included maximum urinary flow (Qmax), postvoid residual (PVR) urine volume, International Prostate Symptom Score (IPSS), including quality of life (QoL) item, at baseline and follow-up visits.. 108 men were enrolled in the trial. Stents were successfully inserted in 97% of the patients. Spontaneous voiding was achieved in all patients. After one month Qmax (+3.7 ml/s), PVR (-99 ml), IPSS (-12) and QoL (-1.7) all showed statistically significant improvements compared to baseline. Substantial improvements, however, were maintained for only one to two months. The main complications were haematuria (19%), urge incontinence (22%), and migration (15%). The median indwelling time was 105 days. The main reason for removal of stents was worsening of symptoms, which might be attributable to the tilting of stents within the prostatic urethra, found upon removal.. Insertion of the bell-shaped nitinol prostatic stent temporarily improves voiding parameters and symptom scores. Because of the limited durability, however, the bell-shaped prostatic stent is not suitable for clinical practice.

Topics: Aged; Alloys; Device Removal; Equipment Safety; Follow-Up Studies; Foreign-Body Migration; Hematuria; Humans; Male; Middle Aged; Prospective Studies; Prosthesis Design; Quality of Life; Severity of Illness Index; Stents; Survival Analysis; Time Factors; Treatment Outcome; Urinary Incontinence; Urination; Urologic Diseases; Urologic Surgical Procedures, Male

Topics: Adult; Alloys; Device Removal; Foreign-Body Migration; Heart Ventricles; Humans; Male; Stents; Tomography, X-Ray Computed

Topics: Adult; Alloys; Cardiac Catheterization; Device Removal; Foreign-Body Migration; Heart Ventricles; Humans; Male; Prosthesis Design; Radiography, Interventional; Stents

Esophageal stenting is a popular form of treatment of esophageal strictures in adults but is not widely used in children. The aim of the current study was to investigate whether esophageal stents could be used safely and effectively in the treatment of esophageal stenosis in children.. Covered retrievable expandable nitinol stents were placed in 8 children with corrosive esophageal stenosis. The stents were removed 1 to 4 weeks after insertion.. The stents were placed in all patients without complications and were later removed successfully. After stent placement, all patients could take solid food without dysphagia. Stent migration occurred in one patient and so the insertion procedure was repeated to reposition the stent. During the 3-month follow-up period after stent removal, all children could eat satisfactorily. After 6 months, 2 children required balloon dilation (3 times in one and 5 times in the other). The dysphagia score improved in all patients.. The use of the covered retrievable expandable stent is an effective and safe method in treating childhood corrosive esophageal stenosis.

Topics: Alloys; Burns, Chemical; Catheterization; Caustics; Chest Pain; Child; Child, Preschool; Conscious Sedation; Deglutition Disorders; Device Removal; Esophageal Stenosis; Female; Fluoroscopy; Follow-Up Studies; Foreign-Body Migration; Humans; Hydrochloric Acid; Hydrogen Peroxide; Male; Pliability; Radiography, Interventional; Severity of Illness Index; Sodium Hydroxide; Stents; Sulfuric Acids; Temperature; Treatment Outcome; Vomiting

Stent embolization is a rare complication in the treatment of central venous stenoses in patients receiving long-term hemodialysis. The authors report a case of nitinol stent embolization into the right atrium in which the stent could not be repositioned across an indwelling permanent inferior vena cava (IVC) filter. The migrated stent was managed by advancing the stent to the superior margin of the IVC filter and then deploying a second suprarenal IVC filter to prevent repeat embolization.

Topics: Alloys; Foreign-Body Migration; Heart Atria; Humans; Male; Middle Aged; Renal Dialysis; Stents; Vena Cava Filters; Vena Cava, Superior

The use of self-expanding metallic stents (SEMS) as esophageal endoprosthesis represents an advancement in the palliation of dysphagia from unresectable esophageal carcinoma. However, the problem of stent migration persists. Although most migrated stents have a benign outcome, complications do occur. Rare reports of intestinal obstruction have been confined to the stiff plastic and stainless-steel stents. We report the first case of intestinal obstruction secondary to the pliable Nitinol SEMS (Ultraflex) migration.

Topics: Adenocarcinoma; Aged; Alloys; Antineoplastic Combined Chemotherapy Protocols; Combined Modality Therapy; Deglutition Disorders; Device Removal; Epirubicin; Equipment Design; Esophageal Neoplasms; Fluorouracil; Foreign-Body Migration; Humans; Ileal Diseases; Intestinal Obstruction; Laparotomy; Liver Neoplasms; Male; Postoperative Complications; Stents

We reviewed the structural findings of explanted AneuRx stent grafts used to treat abdominal aortic aneurysms, and relate the findings to clinical outcome measures.. We reviewed data for all bifurcated AneuRx stent grafts explanted at surgery or autopsy and returned to the manufacturer from the US clinical trial and worldwide experience of more than 33,000 implants from 1996 to 2003. Devices implanted for more than 1 month with structural analysis are included in this article. Explant results were analyzed in relation to cause of explantation and pre-explant evidence of endoleak, enlargement, or device migration.. One hundred twenty explanted stent grafts, including 37 from the US clinical trial, were analyzed. Mean implant duration was 22 +/- 13 months (range, 1-61 months). Structural abnormalities included stent fatigue fractures, fabric abrasion holes, and suture breaks. The mean number of nitinol stent strut fractures per explanted device was 3 +/- 4, which represents less than 0.2% of the total number of stent struts in each device. The mean number of fabric holes per explanted device was 2 +/- 3, with a median hole size of 0.5 mm(2). Suture breaks were seen in most explanted devices, but composed less than 1.5% of the total number of sutures per device. "For cause" explants (n = 104) had a 10-month longer implant duration (P =.007) compared with "incidental" explants (n = 16). "For cause" explants had more fractures (3 +/- 5; P =.005) and fabric holes (2 +/- 3; P =.008) per device compared with "incidental" explants, but these differences were not significant (P =.3) when adjusted for duration of device implantation. Among clinical trial explants the number of fabric holes in grafts in patients with endoleak (2 +/- 3 per device) was no different from those without endoleak (3 +/- 4 per device; P = NS). The number of fatigue fractures or fabric holes was no different in grafts in clinical trial patients with pre-explant aneurysm enlargement compared with those without enlargement. Pre-explant stent-graft migration was associated with a greater number of stent strut fractures (5 +/- 7 per device; P =.04) and fabric holes (3 +/- 3 per bifurcation; P =.03) compared with explants without migration. Serial imaging studies revealed inadequate proximal, distal, or junctional device fixation as the probable cause of rupture or need for conversion to open surgery in 86% of "for cause" explants. Structural device abnormalities were usually remote from fixation sites, and no causal relationship between device findings and clinical outcome could be established.. Nitinol stent fatigue fractures, fabric holes, and suture breaks found in explanted AneuRx stent grafts do not appear to be related to clinical outcome measures. Longer term studies are needed to confirm these observations.

Topics: Aged; Alloys; Aortic Aneurysm, Abdominal; Blood Vessel Prosthesis; Blood Vessel Prosthesis Implantation; Device Removal; Female; Foreign-Body Migration; Humans; Male; Metals; Prosthesis Failure; Stents; Treatment Outcome

To present a single institution experience of long-term results after endovascular repair of abdominal aortic aneurysms (AAA) with the Stentor and Vanguard stent-grafts.. Twenty-three patients (20 men, 3 women; mean age 68 years, range 53-81 years) were included in this prospective study. A first generation nitinol stent-graft (Stentor) was used in 12 patients and a second generation (Vanguard) in 11 patients. Follow-up was performed with magnetic resonance imaging (MRI) with contrast-enhanced MR angiography (CE MRA) at 1, 6, and 12 months, and thereafter annually (median follow-up 3 years; range 8 months to 8 years). A conventional radiograph of the abdomen was also performed. Before secondary intervention the findings on MRI with CE MRA were confirmed with spiral computed tomography (CT) and/or angiography (DSA).. Only one patient (4%) had no complication. Endoleak was found in 15 patients (65%), graft migration in 8 (35%), and graft deformation in 18 (78%). Secondary endovascular repair was required in 7 patients (30%) and 7 (30%) were converted to open repair.. Complications with the Stentor and Vanguard stent-grafts were common. Long-term follow-up of endovascularly repaired AAA is mandatory.

Topics: Aged; Aged, 80 and over; Alloys; Aorta, Abdominal; Aortic Aneurysm, Abdominal; Female; Follow-Up Studies; Foreign-Body Migration; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Angiography; Magnetic Resonance Imaging; Male; Middle Aged; Prospective Studies; Radiography, Abdominal; Stents; Thrombosis; Tomography, Spiral Computed; Treatment Outcome

To evaluate the clot-trapping ability, stability, and migration of a new low-profile, retrievable inferior vena cava (IVC) filter in an in-vitro model.. The SafeFlo IVC filter consists of two superelastic nitinol wires that form a double-ring platform and spiral filter. The filter is collapsed into a 5-6-F catheter and delivered into the IVC model. The in-vitro model closely simulates the physical parameters of flow in the human IVC. Human blood clots of 2-mm and 4-mm diameters and 3-cm lengths were injected into the flow system in sets of five clots. Filter delivery and retrieval were performed in every series. Filtration was evaluated in IVC models of 20-mm and 24-mm lumen diameter in vertical and horizontal positions. Stability and migration of the filter were evaluated by direct vision of maintenance of position and shape before and after clot trapping.. Filter delivery and retrieval were straightforward and repeatable in a total of 20 procedures. The filters maintained shape and position throughout the study. A total of 248 clots were injected and 225 (90.7%) were trapped. The individual tests in horizontal and vertical positions with either clot size demonstrated trapping rates of 85.7%-97.1%.. The SafeFlo IVC filter is a stable and effective filter in an in-vitro model. The filter design is amenable to simple delivery and retrieval.

Topics: Alloys; Blood Coagulation; Coated Materials, Biocompatible; Device Removal; Equipment Design; Equipment Reuse; Equipment Safety; Foreign-Body Migration; Humans; Models, Cardiovascular; Pulmonary Embolism; Vena Cava Filters

The nitinol TrapEase inferior vena cava filter is a new device for pulmonary embolism prophylaxis. No cases of filter migration or filter-related complications with this type of device have so far been described. We report a case of intracardiac migration of this filter in a patient with a patent foramen ovale, resulting in severe cardiogenic shock, cerebral and right arm paradoxical embolism. Surgical treatment, results, causes of these complications are discussed.

Topics: Alloys; Brachial Artery; Cardiac Surgical Procedures; Embolism, Paradoxical; Foreign-Body Migration; Heart Septal Defects, Atrial; Heart Ventricles; Humans; Intracranial Embolism; Male; Middle Aged; Pulmonary Embolism; Vena Cava Filters

To assess whether coaxial placement of uncovered and covered expandable nitinol stents overcomes the disadvantages of the increased migration rate seen with covered stents and the tumor ingrowth seen in uncovered stents in the treatment of malignant gastric outlet obstructions.. Two types of expandable nitinol stent were designed: an uncovered stent and a covered stent. Under fluoroscopic guidance, the uncovered and covered stents were placed coaxially with complete overlap in 39 consecutive patients with malignant gastric outlet obstruction caused by stomach cancer. Food intake capacity was graded on a scale of 0-4. Stent patency rate was estimated by the Kaplan-Meier method.. Technical success rate was 97% (38 of 39 patients). After stent placement, food intake capacity improved at least one grade in 36 patients. Stent migration occurred in three patients (8%), that is, partial (n = 2) or complete (n = 1) upward migration of the inner covered stent into the stomach. Two of these patients were treated by placement of an additional covered stent. During the mean follow-up period of 134 days (range, 15-569 d), 10 patients developed recurrent symptoms of obstruction with tumor overgrowth being the most common cause. Nine underwent placement of an additional covered stent with good results. The median period of primary stent patency was 157 days (mean, 278 d). The 30-, 60-, and 180-day patency rates were 97%, 91%, and 39%, respectively. Four patients (10%) died within 1 month after the procedure.. Coaxial stent placement technique seems to contribute to decreasing the migration rate of the stent and decrease the rate of recurrent obstruction by preventing or delaying tumor ingrowth.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Equipment Design; Feasibility Studies; Female; Foreign-Body Migration; Gastric Outlet Obstruction; Humans; Male; Middle Aged; Stents; Stomach Neoplasms

Topics: Airway Obstruction; Alloys; Bronchial Diseases; Constriction, Pathologic; Foreign-Body Migration; Humans; Stents; Tracheal Stenosis

Topics: Aged; Alloys; Bile Duct Neoplasms; Cholestasis, Extrahepatic; Fatal Outcome; Follow-Up Studies; Foreign-Body Migration; Hepatic Duct, Common; Hernia, Inguinal; Humans; Intestinal Obstruction; Intestine, Small; Male; Prosthesis Failure; Radiography; Reoperation; Rupture; Stents

Topics: Alloys; Carcinoma, Squamous Cell; Endoscopy; Esophageal Neoplasms; Esophageal Stenosis; Foreign-Body Migration; Humans; Palliative Care; Stents

To compare the nitinol occlusion plug with standard stainless steel coils for the occlusion of moderate-size peripheral veins.. The nitinol plug is a braided multilayered vascular occlusion device filled with thrombogenic polyester fibers. It is self-expanding and can be recaptured into its 6-F introducing sheath for repositioning prior to detachment. Ten occlusion procedures were performed in five dogs from a retrograde transjugular venous approach. Five nitinol plugs (diameter: 7.4 mm +/- 0.5) were deployed in five femoropopliteal veins (diameter: 6.5 mm +/- 0.7; mean oversizing 14.6%). Two sequential Gianturco coils (diameter: 7.4 mm +/- 0.9) were deployed in the corresponding contralateral veins (diameter: 6.2 mm +/- 0.8; mean oversizing 19.6%). Follow-up venography was performed at 1 month, following which the animals were killed and the vessels were explanted.. Time-to-occlusion was significantly shorter with the nitinol plug as compared to two Gianturco coils (4.2 minutes +/- 3.4 vs 25.6 minutes +/- 14.1, respectively [P < .03]). At 1 month all but one coil-doublet (80%) had recanalized or migrated, compared to only one nitinol occluder (20%, P < .04). Histopathologic examination of plug-occluded veins showed a uniform organized matrix and underlying intimal proliferative response.. A single nitinol occluder resulted in significantly faster occlusion time and significantly lower recanalization or migration rate than two Gianturco coils, in moderate-size peripheral veins.

Topics: Alloys; Animals; Collateral Circulation; Dogs; Embolization, Therapeutic; Equipment Design; Femoral Vein; Fibrosis; Follow-Up Studies; Foreign-Body Migration; Peripheral Vascular Diseases; Phlebography; Polyesters; Popliteal Vein; Stainless Steel; Statistics as Topic; Time Factors; Tunica Intima

To evaluate the long-term palliative effect of self-expanding nitinol esophageal stents in patients with malignant dysphagia.. One hundred patients with severe dysphagia secondary to malignant esophageal strictures were treated with self-expanding nitinol stents. The strictures were caused by squamous carcinoma (n = 43), adenocarcinoma (n = 28), anastomotic tumor recurrence (n = 14), and mediastinal tumor (n = 15).. One hundred six stents were successfully positioned in 100 patients. Attempts to insert a second, coaxial stent were unsuccessful in two patients; a second stent was placed incorrectly in another patient. Statistically significant (P < .001) reduction of dysphagia was noted after expansion of the stents. Complications consisted of incomplete expansion secondary to stent twisting (n = 4), stent migration (n = 4), tumor ingrowth (n = 17), tumor overgrowth (n = 3), food impaction (n = 5), fracture of stent wires (n = 2), benign strictures at stent edges (n = 2), tumor bleeding (n = 3), and esophagorespiratory fistula (n = 5). The primary patency rate was 75% (77 of 102 stents); the secondary patency rate was 94% (96 of 102 stents). The survival time (mean, 6.2 months; range, 0.1-47 months) varied with the diagnosis.. Placement of self-expanding nitinol stents is safe and has a good long-term palliative effect on dysphagia in patients with malignant esophageal strictures.

Topics: Adenocarcinoma; Adult; Aged; Aged, 80 and over; Alloys; Anastomosis, Surgical; Carcinoma, Squamous Cell; Deglutition Disorders; Equipment Design; Equipment Failure; Esophageal Fistula; Esophageal Neoplasms; Esophageal Stenosis; Evaluation Studies as Topic; Female; Follow-Up Studies; Food; Foreign-Body Migration; Hemorrhage; Humans; Longitudinal Studies; Male; Mediastinal Neoplasms; Middle Aged; Neoplasm Recurrence, Local; Palliative Care; Respiratory Tract Fistula; Stents; Surface Properties; Survival Rate

Our purpose was to evaluate a new prosthesis for percutaneous closure of secundum atrial septal defects (ASDs).. Percutaneous closure of surgically created fossa ovalis ASD was attempted in 15 minipigs. The mean balloon-stretched ASD diameter was 12.3+/-2.3 mm (range, 10 to 16 mm). The self-expanding prosthesis was braided from 0.005-in Nitinol wires in the shape of two flat buttons with a short connecting waist with a diameter corresponding to that of the defect to be closed. Polyester filling was added to enhance thrombogenicity. Pulmonary arteriography with levo-phase was obtained before placement; immediately after placement; and at 1-week, 1-month, and 3-month follow-ups. Four animals were killed at 1 week, 1 month, and 3 months for histopathological correlation. Three deaths resulted from ventricular fibrillation (one during anesthesia and two during the placement procedure). Successful placement of the prosthesis was achieved in the remaining 12 animals. Overall immediate ASD closure on angiography occurred in 7 of 12 animals (all polyester-filled prostheses). Absent or trace shunt by angiography was present in 11 of 12 devices at 1 week, with the remaining one demonstrating a small shunt. All septal defects were completely closed at 1 month with the exception of one case in which delayed partial dislodgment of an undersized prosthesis into the right atrium had developed. Closure rate at 3 months was 100%. Neoendothelialization and fibrous incorporation of the prosthesis were completed within 1 to 3 months.. Effective and permanent occlusion of secundum ASDs is feasible with a device that offers the advantages of easy placement, self-centering, and repositionability.

Topics: Alloys; Animals; Cardiac Catheterization; Endocardium; Femoral Vein; Foreign-Body Migration; Heart Septal Defects, Atrial; Jugular Veins; Postoperative Complications; Prostheses and Implants; Prosthesis Design; Swine; Swine, Miniature; Ventricular Fibrillation; Wound Healing

Simon nitinol vena caval filters were placed percutaneously in 20 patients. Follow-up (average, 14 months) data were available for 16 patients, and four patients were lost to follow-up. There were no proved or suspected cases of pulmonary embolism after filter insertion. Complications encountered included caval penetration (n = 5, one acute and four at follow-up), caval thrombus (n = 4, two determined radiologically and two clinically), postplacement deep venous thrombosis (n = 2, one radiologic and one clinical), filter migration (n = 1), and delayed fracture of a filter leg (n = 2). Although no deaths or significant morbidity resulted from any complication, the relatively high complication rate, especially of significant caval penetration (documented in 25% of filter insertions), merits continued short- and long-term assessment of patient status after filter placement.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Female; Foreign-Body Migration; Humans; Male; Middle Aged; Pulmonary Embolism; Radiography; Thrombosis; Vena Cava Filters; Vena Cava, Inferior