Covered Versus Uncovered Wallstent for Malignant Extrahepatic Biliary Obstruction: A Cohort Comparative Analysis

Background & Aims: We examined the use of both covered and uncovered Wallstents in patients with malignant extrahepatic biliary obstruction to determine whether use of covered Wallstents prolonged stent patency without increasing procedure-related complications. Methods: Commercially available silicone-covered Wallstents were prospectively evaluated in 98 patients who underwent insertion from December 2002–December 2004. Those data were compared with data obtained by retrospectively studying 108 consecutive patients who underwent endoscopic insertion of uncovered Wallstents between January 2000–November 2002, and for whom accurate and complete follow-up details were available. Results: The mean stent patency was similar for both groups, 148.9 days (range, 3–667 days) for covered Wallstents and 143.5 days (3–910 days) for uncovered Wallstents (P = .531). The 2 groups also did not significantly differ in terms of cumulative stent patency according to the Kaplan-Meier lifetime table. The incidence of mild pancreatitis was similar in both groups, occurring in 6 patients with covered stents (6/98, 6.1%) and 2 patients with uncovered stents (2/108, 1.9%) (P = .154). Excluding those patients who had previously undergone cholecystectomy, acute cholecystitis occurred in 5 of 88 patients with covered Wallstents (6.1%) and 1 of 100 patients with uncovered stents (1%) (P = .104). Stent migration occurred in 6 patients with covered stents (6.1%) and 0 patients with uncovered stents (P = .011). Conclusion: Covered Wallstents might not prolong stent patency compared with uncovered Wallstents when used in the management of malignant extrahepatic biliary obstruction.