A comparison of uncovered metal stents for the palliation of patients with malignant biliary obstruction: Nitinol vs. stainless steel

Background: Various types of self-expandable metal stents have been introduced for the palliation of malignant biliary obstruction. Aims: To compare the outcomes of WallFlex (TM) and Wallstent (TM) uncovered biliary self-expandable metal stents (SEMSs) for the palliation of patients with malignant biliary obstruction. Methods: Between October 2008 and December 2009, all SEMSs placed for malignant biliary obstruction were WaIlFlex (TM): all patients palliated were included in the study. Before October 2008, all the SEMSs placed for malignant biliary obstruction were Wallstent (TM), and the patients palliated from July 2007 to September 2008 were the comparative group. Results: A total of 58 WallFlex (TM) and 54 Wallstent (TM) SEMSs were placed, and efficacious biliary decompression was achieved in all patients. Early complications occurred in 5 patients in the WallFlex (TM) group and in 3 in the Wallstent (TM) group (p = ns). Late complications occurred in 6 patients in the WallFlex (TM) group and in 16 in the Wallstent (TM) group (p < 0.01). The overall patency of the self-expandable metal stein in the WallFlex (TM) and the Wallstent (TM) groups was similar (227 days vs. 215 days, p = ns). Mean patient survival was 242 days in the WallFlex (TM) group and 257 days in the Wallstent (TM) group (p = ns). Conclusions: We found no difference in terms of overall patency between the two types of SEMSs, but there was an increased rate of late adverse events in the Wallstent (TM) group. (C) 2011 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.