nitinol and Gastric-Outlet-Obstruction

A conformable self-expandable metallic stent was developed to overcome the limitation of previous self-expandable metallic stents. The aim of this study was to evaluate outcomes after placement of conformable covered and uncovered self-expandable metallic stents for palliation of malignant gastroduodenal obstruction.. A single-blind, randomized, parallel-group, prospective study were conducted in 4 medical centres between March 2009 and July 2012. 134 patients with unresectable malignant gastroduodenal obstruction were assigned to a covered double-layered (n=66) or uncovered unfixed-cell braided (n=68) stent placement group. Primary analysis was performed to compare re-intervention rates between two groups.. 120 patients were analysed (59 in the covered group and 61 in the uncovered group). Overall rates of re-intervention were not significantly different between the two groups: 13/59 (22.0%) in the covered group vs. 13/61 (21.3%) in the uncovered group, p=0.999. Stent migration was more frequent in the covered group than in the uncovered group (p=0.003). The tumour ingrowth rate was higher in the uncovered group than in the covered group (p=0.016).. The rates of re-intervention did not significantly differ between the two stents. Conformable covered double-layered and uncovered unfixed-cell braided stents were associated with different patterns of stent malfunction.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Digestive System Neoplasms; Duodenal Obstruction; Female; Gastric Outlet Obstruction; Humans; Male; Middle Aged; Palliative Care; Prospective Studies; Prosthesis Failure; Retreatment; Single-Blind Method; Stents

A high incidence of migration with covered metal stents has been reported in malignant gastric outlet obstruction (GOO). A newly modified, partially covered, triple-layer nitinol stent was developed that has a longer uncovered portion (5-15 mm) to prevent stent migration.. To estimate the efficacy and safety of the modified covered, triple-layer metal stent.. Multicenter, prospective cohort study.. Three tertiary referral centers.. Fifty consecutive patients (26 with pancreatic carcinoma, 14 with gastric carcinoma, 9 with cholangiocarcinoma, 1 with a metastatic node) who presented with symptomatic unresectable malignant GOO between April 2007 and March 2010.. Endoscopic placement of the modified covered, triple-layer metal stent.. The primary endpoint was to improve the GOO scoring system (GOOSS) score. Secondary endpoints were success rate, patency, and complications.. The median GOOSS score improved significantly (P < .0001) after stenting (from 0 to 3). The technical and clinical success rates were 100% and 90%, respectively. Stent occlusion by tumor overgrowth or ingrowth at the uncovered portion developed in 5 patients (10%). Asymptomatic stent migration occurred in 3 patients (6%) receiving chemotherapy at 95, 230, and 553 days after stent placement, but these patients tolerated solid food 68, 260, and 142 days after stent migration, respectively. Other complications occurred in 1 patient with insufficient expansion, cholangitis, and pancreatitis. No procedure-related deaths occurred.. A single-arm study in tertiary-care centers.. The modified covered, triple-layer metal stent was effective and safe for managing malignant GOO and can prevent tumor ingrowth and stent migration. (. UMIN000004566.).

Topics: Aged; Alloys; Bile Duct Neoplasms; Carcinoma; Cholangiocarcinoma; Female; Gastric Outlet Obstruction; Humans; Kaplan-Meier Estimate; Male; Middle Aged; Pancreatic Neoplasms; Prosthesis Failure; Stents; Stomach Neoplasms

Topics: Adult; Aged; Aged, 80 and over; Alloys; Endoscopes; Endoscopy; Esophageal Neoplasms; Female; Gastric Outlet Obstruction; Humans; Male; Middle Aged; Palliative Care; Prognosis; Prospective Studies; Stents; Stomach Neoplasms

To determine the safety and efficacy of endoscopic duodenal stent placement in patients with malignant gastric outlet obstruction.. This prospective, observational, multicenter study included 39 consecutive patients with malignant gastric outlet obstruction. All patients underwent endoscopic placement of a nitinol, uncovered, self-expandable metal stent. The primary outcome was clinical success at 2 wk after stent placement that was defined as improvement in the Gastric Outlet Obstruction Scoring System score relative to the baseline.. Technical success was achieved in all duodenal stent procedures. Procedure-related complications occurred in 4 patients (10.3%) in the form of mild pneumonitis. No other morbidities or mortalities were observed. The clinical success rate was 92.3%. The mean survival period after stent placement was 103 d. The mean period of stent patency was 149 d and the patency remained acceptable for the survival period. Stent dysfunction occurred in 3 patients (7.7%) on account of tumor growth.. Endoscopic management using duodenal stents for patients with incurable malignant gastric outlet obstruction is safe and improved patients' quality of life.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Digestive System Neoplasms; Duodenoscopes; Duodenoscopy; Female; Gastric Outlet Obstruction; Humans; Japan; Male; Middle Aged; Prospective Studies; Prosthesis Design; Stents; Time Factors; Treatment Outcome

This retrospective study estimated the efficacy and safety of the WallFlex duodenal stent for malignant gastric outlet obstruction (GOO) in Japan.. Forty-two consecutive patients with symptomatic malignant GOO were treated using WallFlex duodenal stents between January 2010 and October 2010.. The technical and clinical success rates were 100% and 83.3%, respectively.The median gastric outlet obstruction scoring system increased significantly, from 0 to 2, after stent placement (P < 0.01).The median survival time was 3.3 months (95% confidence interval (CI), 1.8-6.0 months), and the median eating period was 3.0 months (95% CI, 1.1-4.3 months). Re-intervention was required in 11 patients (26.2%). The complication rate was 26.2%. The major complication was stent occlusion (23.8%) by tumor ingrowth, which occurred in nine (21.4%) patients, and tumor overgrowth, which occurred in one (2.4%) patient. Stentmigration, perforation, and food impaction without stent occlusion were not observed.The median survival time of the patients with stent occlusion was 11.7 months (95% CI, 2.2 months - not reached), and the median stent patency of these patients was 4.0 months (95% CI, 0.8-4.7 months).These patients were successfully treated with additional stent insertion using a stent-in-stent procedure.. Duodenal stent placement using a WallFlex duodenal stent was safe and effective for managing malignant GOO.This stent is an uncovered metallic stent, and the major problem was stent occlusion due to tumor ingrowth. However, the occluded stent could be corrected by inserting an additional duodenal stent.

Topics: Aged; Aged, 80 and over; Alloys; Cholangiopancreatography, Endoscopic Retrograde; Contrast Media; Duodenum; Female; Fluoroscopy; Gastric Outlet Obstruction; Gastroscopy; Humans; Japan; Male; Middle Aged; Postoperative Complications; Prosthesis Design; Retrospective Studies; Statistics, Nonparametric; Stents; Stomach Neoplasms; Survival Rate; Treatment Outcome

Duodenal stenting has become a broadly accepted first line of treatment for patients with advanced malignant gastroduodenal obstruction as these patients are difficult to treat and are poor surgical candidates.. To document duodenal stent performance for palliative management of malignant gastroduodenal obstruction.. Multicentre, single arm, prospective registry documenting peroral endoscopic duodenal stenting procedures in 202 patients.. Technical success achieved in 98% (CI, 95%, 99%) of stent placements. Increase of Gastric Outlet Obstruction Score by at least 1 point compared to baseline was achieved in 91% (CI, 86%, 95%) of patients persisting for a median of 184 days (CI, 109, 266). By day 5 (CI, 4, 6) after stent placement, 50% of patients experienced a score increase of at least 1 point. Improvement from 14% of patients at baseline tolerating soft solids or low residue/normal diet to 84% at 15 days, 86% at 30 days, 81% at 90 days, 79% at 180 days, and 70% at 270 days. Complications included stent ingrowth and/or overgrowth (12.4%), transient periprocedural symptoms (3%), bleeding (3%), stent migration (1.5%), and perforation (0.5%).. Safety and effectiveness of duodenal stenting for palliation of malignant gastroduodenal obstruction was confirmed in the largest international prospective series to date.

Topics: Alloys; Duodenal Obstruction; Endoscopy, Gastrointestinal; Female; Follow-Up Studies; Gastric Outlet Obstruction; Gastrointestinal Neoplasms; Humans; Male; Prospective Studies; Prosthesis Design; Registries; Stents; Survival Analysis

The objective of our study was to assess the incidence, predictive factors, and treatment of tumor overgrowth after placement of expandable metallic dual stents in patients with malignant gastroduodenal obstruction.. Expandable metallic dual stents were inserted under fluoroscopic guidance in 583 patients with symptomatic malignant gastroduodenal obstruction. We retrospectively reviewed prospectively collected patient records to determine the incidence and treatment of tumor overgrowth after stent placement and used multivariate analysis to determine factors predicting tumor overgrowth.. Tumor overgrowth occurred after stent placement in 22 of 583 patients (3.8%) (range, 41-634 days; mean, 179.0 days). Duodenal lesions (odds ratio [OR], 4.505; p = 0.002), longer survival time (OR, 1.003; p = 0.001), and length of obstruction (OR, 0.783; p = 0.035) were independent predictors of tumor overgrowth. Twenty of the 22 patients were successfully treated by placement of a second dual stent, whereas the other two patients refused placement of a second stent or other further treatment. Overall, 19 of 20 patients (95%) showed improvement in symptoms after second stent placement. Duodenal perforation occurred in one of the 20 patients 125 days after placement of a second stent and was treated surgically.. Tumor overgrowth seems to be an uncommon complication of expandable metallic dual stent placement in patients with malignant gastroduodenal obstruction. Tumor overgrowth is associated with duodenal lesions, longer survival time, and shorter stricture length. Tumor overgrowth can be successfully managed by coaxial insertion of a second dual-expandable metallic stent into the obstructed first stent.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Alloys; Contrast Media; Duodenal Obstruction; Female; Fluoroscopy; Follow-Up Studies; Gastric Outlet Obstruction; Humans; Incidence; Male; Middle Aged; Multivariate Analysis; Prosthesis Design; Radiography, Interventional; Retrospective Studies; Stents

Gastric outlet obstruction (GOO) is a late complication of advanced gastric, periampullary, and duodenal malignancies. Palliation of obstruction is the primary aim of treatment in these patients. Self-expandable metal stents have emerged as a promising treatment option. Our aim was to investigate the safety and efficacy of a new non-foreshortening nitinol duodenal stent.. A total of 52 patients with symptomatic malignant GOO were studied in this prospective multicenter cohort study. All patients received a D-Weave Niti-S duodenal stent (Taewoong Medical, Seoul, South Korea). Patients were followed up until withdrawal of informed consent or death.. The cause of GOO was pancreatic cancer in the majority of patients (62%). The technical and clinical success rates were 96% and 77%, respectively. The GOO Scoring System score improved significantly (P < 0.0001) when the scores before stenting were compared with the mean scores until death. Median survival was 82 days and stent patency was observed in 75% for up to 190 days, accounting for death as a competing risk. In 13 patients (25%) stent dysfunction occurred (tumor ingrowth in 11, stent migration in two). Over time, the body mass index, the World Health Organization performance score, and the EuroQol visual analog scale revealed a not significant change (P = 0.52, P = 0.43, and P = 0.15, respectively), whereas the global health status improved significantly (P = 0.001).. Placement of a new non-foreshortening nitinol enteral stent is safe and without major complications. This stent design produces significant relief of obstructive symptoms and improves quality of life in patients with incurable malignant GOO.

Topics: Aged; Alloys; Digestive System Neoplasms; Female; Gastric Outlet Obstruction; Humans; Male; Middle Aged; Palliative Care; Prospective Studies; Prosthesis Failure; Quality of Life; Statistics, Nonparametric; Stents

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

We sought to test the hypothesis that placement of a new nitinol duodenal self-expandable metallic stent (SEMS) for palliation of malignant gastroduodenal obstruction is effective and safe in allowing patients to tolerate an oral diet.. In a prospective multicenter study, SEMSs (Duodenal WallFlex, Boston Scientific) were placed to alleviate gastroduodenal obstruction in inoperable patients without the ability to tolerate solid food. The primary study end point was improvement in oral intake monitored according to the 4-point Gastric Outlet Obstruction Scoring System (GOOSS) up to 24 weeks after stent placement.. Forty-three patients received SEMSs, which were successfully deployed on the first attempt in 41 cases (95%) and the second attempt in two (5%). Within 1 day and 7 days after SEMS placement, 52% and 75% of patients, respectively, benefited from a GOOSS increase > or =1. Resumption of solid food intake (GOOSS 2-3) was attained by 56% of patients within 7 days and 80% by 28 days. Of the patients attaining GOOSS 2-3, 48% remained on solid food until death or last follow-up. Device-related adverse events included stent occlusion/malfunction in 9% of patients and perforation in 5% of patients.. Duodenal WallFlex stent placement promptly improves oral intake in a majority of inoperable patients with malignant gastroduodenal obstruction. In approximately half the patients achieving GOOSS 2-3, the capacity for solid food intake endures until death or last follow-up.

Topics: Alloys; Diet; Duodenum; Female; Gastric Outlet Obstruction; Humans; Male; Middle Aged; Neoplasms; Palliative Care; Prospective Studies; Risk Factors; Stents; Treatment Outcome

The aim of the present study was to investigate the clinical effectiveness, safety, and outcome associated with the use of covered expandable Nitinol stents (Taewoong Medical, Seoul, Korea) for the treatment of malignant gastroduodenal obstructions.. Between March 2001 and October 2004, covered expandable Nitinol stents were placed in 68 consecutive patients under endoscopic and fluoroscopic guidance for the following reasons: gastric carcinoma (n = 49), recurrent carcinoma after partial gastrectomy (n = 7), or another malignant neoplasm involving the duodenum (n = 12).. Technical success was achieved in 60 of the 68 patients (88.2%). After stent placement, mean dysphagia score improved from a mean of 3.5 to 1.2 (P < 0.001). The mean period of primary stent patency was 107.2 days. During follow up (mean 4.4 months; range, 1-15 months), major complications (migration [6], bleeding [3], perforation [1], ingrowth [1], overgrowth [7], fistula [1]) occurred in 19 patients (27.9%), and stent migration occurred in six (8.8%) (proximal migration into the stomach [n = 3], or distal migration [n = 3]). Recurrent dysphagia (mainly due to tumor ingrowth/overgrowth) occurred in eight patients (11.8%).. Covered expandable Nitinol stents appear to offer an effective and feasible palliative therapy in patients with a malignant gastroduodenal obstruction.

Topics: Aged; Alloys; Duodenal Obstruction; Duodenoscopy; Female; Gastric Outlet Obstruction; Gastrointestinal Neoplasms; Gastroscopy; Humans; Male; Middle Aged; Palliative Care; Prosthesis Design; Retrospective Studies; Stents; Time Factors; Treatment Outcome

Metallic stents are a therapeutic option for patients with malignant GI obstruction.. Our purpose was to evaluate the clinical effectiveness of a self-expandable metallic stent in 213 patients with malignant gastroduodenal obstruction and to identify prognostic factors associated with clinical outcomes.. Prospective cohort study.. Single tertiary referral university hospital.. Two hundred thirteen consecutive patients with symptomatic malignant gastric outlet or duodenal obstruction from 2001 to 2005.. Placement of a self-expandable metallic stent.. Prospective data collection focused on technical and clinical success, complications, and prognostic factors associated with stent patency.. Technical and clinical success were achieved in 94% and 94% of the patients, respectively, and the complication rate was 21%. The median and mean survival periods were 99 (95% CI, 78-121) and 159 days (95% CI, 116-203). The median and mean stent patency periods were 270 (95% CI, 234-413) and 324 days (95% CI, 128-412). With use of the multivariate Cox proportional hazard model, chemotherapy after stent placement (odds ratio, 0.19; 95% CI, 0.08-0.46; P < .001) was significantly associated with an increase in the maintenance of stent patency.. Single-center experience and the lack of a control group.. Placement of a self-expandable metallic stent is clinically effective in patients with unresectable gastric outlet or duodenal obstruction. Chemotherapy after stent placement, albeit associated with increased migration rates, is associated with an increase in the maintenance of stent patency.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Alloys; Duodenal Obstruction; Endoscopy, Gastrointestinal; Female; Fluoroscopy; Gastric Outlet Obstruction; Gastrointestinal Neoplasms; Humans; Male; Middle Aged; Palliative Care; Stents

Through-the-scope (TTS) stents facilitate palliative enteral stent placement. However, most TTS stents are braided, a characteristic that has been associated with significant foreshortening and relatively frequent migration.. To evaluate clinical experience with a new woven enteral stent in the treatment of gastric outlet obstruction.. From January 2005 to August 2006, patients with unresectable malignant gastric outlet obstruction were offered stent placement with a new woven stent.. Three referral hospitals in Japan.. Thirty-seven consecutive patients with malignant gastric outlet obstruction.. A newly designed enteral stent was placed by using the TTS placement technique.. Palliation efficacy and safety of the new stents.. Stent placement was successful in 36 of 37 patients (technical success, 97%). Thirty-four patients were able to tolerate oral intake without obstructive symptoms (clinical success, 94.4%). Complications occurred in 16.2% of patients, comprising 2 cases of primary stent dysfunction, 1 perforation, 1 GI bleeding, 1 stent obstruction, and 1 biliary stent dysfunction. No migration was seen during the median follow-up period of 68 days.. Small sample size and relatively brief follow-up.. A newly developed enteral stent with higher flexibility and less foreshortening offers comparable clinical outcome to existing stents and a lower frequency of complications, including migration.

Topics: Aged; Alloys; Equipment Design; Female; Gastric Outlet Obstruction; Humans; Male; Middle Aged; Palliative Care; Pancreatic Neoplasms; Stents; Stomach Neoplasms; Survival Rate

To investigate the technical feasibility and clinical effectiveness of a dual expandable nitinol stent in the palliative treatment of malignant gastroduodenal strictures.. The dual stent consisted of two stents, an outer partially covered stent and an inner bare nitinol stent. The outer diameter of the stent delivery system was 3.8 mm. With fluoroscopic guidance, the outer stent was placed into the stricture, followed by coaxial placement of the inner stent. The stent placement was attempted in 102 consecutive patients with malignant gastroduodenal strictures. The underlying causes of malignant strictures were gastric cancer (n = 55), pancreatic cancer (n = 24), gallbladder cancer (n = 7), cholangiocarcinoma (n = 5), duodenal cancer (n = 5), and metastatic cancer (n = 6). All patients presented with symptoms of gastric outlet obstruction.. Stent placement was technically successful and well tolerated in 101 of 102 patients (99%). After stent placement, 85 of the 101 patients (84%) with technical success experienced improvement of their symptoms. Tumor overgrowth occurred in five patients, stent migration in two, mucosal hyperplasia in one, bleeding in one, and jaundice in two. Seventy one of the 101 patients died 5 to 340 days (mean, 71 days) after stent placement from progression of their disease, myocardial infarction, bleeding, or sepsis. The remaining 30 patients are still alive 6 to 227 days (mean, 39 days) after stent placement. The 30-day, 60-day, 90-day, and 180-day survival rates were 78%, 58%, 39%, and 8%, respectively.. The dual stent with a 3.8-mm stent delivery system is easy to insert, safe, and reasonably effective for the palliative treatment of malignant gastroduodenal strictures.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Constriction, Pathologic; Duodenal Obstruction; Feasibility Studies; Female; Fluoroscopy; Gastric Outlet Obstruction; Humans; Male; Middle Aged; Palliative Care; Pilot Projects; Radiography, Interventional; Statistics, Nonparametric; Stents; Survival Analysis; Treatment Outcome

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

Insertion of metallic stents for esophageal stenoses is well established, but these stents are technically difficult to place elsewhere in the GI tract. Moreover, major complications have occurred when metal stents with sharp ends have been placed in these locations. The currently available flexible, blunt-ended, knitted nitinol stent is intended for use only in the esophagus. Because its short delivery system cannot reach segments of the gut distal to the esophagus, the delivery device was modified to facilitate intestinal access, and its performance was evaluated in the treatment of malignant intestinal obstructions.. The Ultraflex delivery system was modified by connecting an additional plastic tube and a suture cord; the length was increased from 95 cm to 150 cm or more. Stents used were 18 to 23 mm in diameter, and 10 to 15 cm in length. A knitted metal stent was inserted by using the modified delivery system in 10 patients (7 men, 3 women, mean age 68 years); 8 with gastric outlet, 1 with jejunal, and 1 with proximal colonic obstruction.. Metal stent insertion was successful in all patients with significant relief of symptoms and restoration of the ability to eat. The patient with a jejunal stent required placement of a second stent because of bending of the initial stent. No major complications (migration or perforation) occurred.. This technique appears to facilitate placement of a metal stent with blunt ends in the duodenum, small intestine, and proximal colon. Manufacturers should offer blunt-ended stents with long delivery devices.

Topics: Aged; Alloys; Equipment Design; Female; Gastric Outlet Obstruction; Humans; Intestinal Obstruction; Male; Stents

To investigate the technical feasibility and clinical effectiveness of a polyurethane-covered expandable nitinol stent in the treatment of malignant gastroduodenal obstructions.. The stent was constructed in-house by weaving a single thread of 0.2-mm nitinol wire in a tubular configuration and was covered with polyurethane solution by means of a dipping method. With fluoroscopic guidance, the stent was placed in 19 consecutive patients with malignant gastric outlet obstruction (n = 15) or duodenal obstruction (n = 4). All patients had severe nausea and recurrent vomiting, and their obstructions were inoperable.. Stent placement was technically successful in all but one patient. After stent placement, symptoms improved in all but one patient, who had another stenosis at the proximal jejunum. One patient with stent placement in the second portion of the duodenum became jaundiced. During the mean follow-up of 11 weeks, stent migration occurred in five patients 1-4 days after the procedure. All patients with stent migration were treated by means of placing a second, uncovered nitinol stent. Two of these five patients showed recurrence of stricture because of tumor ingrowth; they underwent coaxial placement of a third, covered nitinol stent with good results.. Placement of a polyurethane-covered expandable nitinol stent seems to be technically feasible and effective for palliative treatment of inoperable malignant gastroduodenal obstructions. Stent migration, however, is problematic and requires further investigation.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Coated Materials, Biocompatible; Duodenal Neoplasms; Duodenal Obstruction; Feasibility Studies; Female; Gastric Outlet Obstruction; Humans; Male; Middle Aged; Palliative Care; Pancreatic Neoplasms; Polyurethanes; Prosthesis Design; Prosthesis Failure; Pyloric Stenosis; Radiography; Stents; Stomach Neoplasms