Fully covered stents are similar to semi-covered stents with regard to migration in palliative treatment of malignant strictures of the esophagus and gastric cardia: results of a randomized controlled trial.

INTRODUCTION: Stent migration is a significant clinical problem in palliation of malignant strictures in the esophagus and gastro-esophageal junction (GEJ). We have compared a newer design of a fully-covered stent to a widely used semi-covered stent using migration >20 mm as the primary outcome variable. Effects on dysphagia, quality of life (QoL) and re-intervention frequency were also investigated. METHODS: Patients with dysphagia due to non-curable esophagus/GEJ cancer were randomized to receive either a more recent design of a fully-covered stent (n = 48) or a conventional semi-covered stent (n = 47). Chest x-ray, dysphagia and QoL were studied at baseline, one week, four weeks and three months thereafter. RESULTS: There were no significant differences either in stent migration distance or in the migration frequency. Stent migration during the total study period occurred in 37.2 % in the semi-covered group compared to 20.0 % for the fully-covered group. Dysphagia was measured with Watson and Ogilvie scores and with the dysphagia module in the QoL scale (QLQ-OG25). On average, there was a tendency to better dysphagia relief for the fully-covered design as scored with the two latter dysphagia instruments (p= 0.081 and p= 0.067) at three months and towards more re-interventions in the semi-covered group (p= 0.083). CONCLUSION: In spite of its somewhat lower intrinsic radial force, the fully-covered stent was comparable to the conventional semi-covered stent with regard to stent migration. The data further suggest a potential benefit of the fully-covered stent in improving dysphagia in patients with longer life expectancy.

Nitinol versus steel partially covered self-expandable metal stent for malignant distal biliary obstruction: a randomized trial.

BACKGROUND AND STUDY AIMS: Covered nitinol alloy self-expandable metal stents (SEMSs) have been developed to overcome the shortcomings of steel SEMS in patients with malignant biliary obstruction. In a randomized, multicenter trial, we compared stent patency, patient survival, and adverse events in patients with partly covered stents made from steel or nitinol. PATIENTS AND METHODS: A total of 400 patients with unresectable distal malignant biliary obstruction were randomized at endoscopic retrograde cholangiopancreatography (ERCP) to insertion of a steel or nitinol partially covered SEMS, with 200 patients in each group. The primary outcome was confirmed stent failure during 300 days of follow-up.  RESULTS: At 300 days, the proportion of patients with patent stents was 77 % in the steel group, compared with 89 % in the nitinol group (P = 0.01). Confirmed stent failure occurred more often in the steel SEMS group compared with the nitinol SEMS group, in 30 versus 14 patients (P = 0.02). Stent migration occurred in 13 patients in the steel group and in 3 patients in the nitinol group (P = 0.01). Median patient survival (secondary outcome) was 137 days and 120 days in the steel SEMS and nitinol SEMS groups, respectively (P = 0.59). CONCLUSIONS: The nitinol SEMS showed longer patency time, and the nitinol group had fewer patients with stent failure, compared with the steel SEMS group. We could not detect any differences between the two groups regarding survival time, and regarding adverse event rate.Clinical trial registration : NCT 00980889.

Covered versus uncovered self-expandable nitinol stents in the palliative treatment of malignant distal biliary obstruction: results from a randomized, multicenter study.

BACKGROUND: Covered biliary metal stents have been developed to prevent tumor ingrowth. Previous comparative studies are limited and often include few patients. OBJECTIVE: To compare differences in stent patency, patient survival, and complication rates between covered and uncovered nitinol stents in patients with malignant biliary obstruction. DESIGN: Randomized, multicenter trial conducted between January 2006 and October 2008. SETTING: Ten sites serving a total catchment area of approximately 2.8 million inhabitants. PATIENTS: A total of 400 patients with unresectable distal malignant biliary obstruction. INTERVENTIONS: ERCP with insertion of covered or uncovered metal stent. Follow-up conducted monthly for symptoms indicating stent obstruction. MAIN OUTCOME MEASUREMENTS: Time to stent failure, survival time, and complication rate. RESULTS: The patient survival times were 116 days (interquartile range 242 days) and 174 days (interquartile range 284 days) in the covered and uncovered stent groups, respectively (P = .320). The first quartile stent patency time was 154 days in the covered stent group and 199 days in the uncovered stent group (P = .326). There was no difference in the incidence of pancreatitis or cholecystitis between the 2 groups. Stent migration occurred in 6 patients (3%) in the covered group and in no patients in the uncovered group (P = .030). LIMITATIONS: Randomization was not blinded. CONCLUSIONS: There were no significant differences in stent patency time, patient survival time, or complication rates between covered and uncovered nitinol metal stents in the palliative treatment of malignant distal biliary obstruction. However, covered stents migrated significantly more often compared with uncovered stents, and tumor ingrowth was more frequent in uncovered stents.