Comparison of the Utility of Covered vs. Uncovered Metal Stents in the Management of Malignant Biliary Strictures in 749 Patients Presidential Poster

Abstract

Table: [227] Patient characteristicsPurpose: To compare the stent patency rate, overall survival, and complications between covered self-expanding metal stent (CSEMS) and uncovered self-expanding metal stent (USEMS) in malignant biliary obstruction. Methods: The study is a retrospective cohort study in a single tertiary cancer center. Patients who met the following criteria during the period of January 2000 and June 2011 were included in the study. Inclusion criteria: 1) all patients with malignant biliary obstruction presenting for ERCP, biliary decompression and first-time metal stent placement, and 2) all patients with history of malignant biliary obstruction and preceding plastic biliary stent referred for the first metal stent. Results: There were 749 patients who met the inclusion criteria. Of these, 171 received CSEMS and 578 received USEMS. There was no difference between the groups in term of gender or pancreatic cancer status. Among all patients, no differences between patients receiving CSEMS and USEMS were found in terms of overall survival (OS) or time to recurrent biliary obstruction (RO). Median OS (95% confidence interval [CI]) was 10.4 (8.9, 12.5) months for patients with CSEMS and 11.7 (10.1, 13.1) months for USEMS (p=0.84). The median (min, max) RO was 6.2 (0.2, 71.5) months for patients with CSEMS and 4.05 (0.2, 28.6) months for USEMS (p=0.01). The hazard ratio for RO was 1.06 (95% CI 0.70-1.58) comparing the two groups. While there was no difference in the proportion of patients with RO between stent types (p=0.61), the type of obstruction differs substantially by stent type (p<0.001) with tumor ingrowth occurring in 76% of obstructed patients with USEMS compared to 9% for CSEMS. Obstructed patients with CSEMS were more likely to experience tumor overgrowth (15% vs. 2%), sludge stone (18% vs. 3%), food debris (12% vs. 5%), and stent migration (36% vs. 2%) compared to USEMS. Among all patients, acute pancreatitis (AP) was more likely to occur with CSEMS (12 [6%]; 10 mild, 1 moderate, 1 severe) vs. USEMS (6 [1%]; 4 mild, 1 moderate, 1 severe; p<0.001). Sixty-one patients underwent the procedures as outpatients. One hundred and nine patients (98 with pancreatic cancer) underwent surgery with SEMS in place, including 107 pancreaticoduodenectomy. There were no stent-related intraoperative or post-operative complications. Conclusion: There was no significant difference in the patency rate or overall survival between the two groups. No significant differences were seen in the rate of cholecystitis or cholangitis between the two groups. However, CSEMS had a significantly higher rate of migration and pancreatitis. No significant SEMS-related complications were seen in chemoradiation or surgery.Table: Complications