Comparison of partially covered nitinol stents with partially covered stainless stents as a historical control in a multicenter study of distal malignant biliary obstruction: the WATCH study

摘要: Background Covered self-expandable metal stents (CSEMSs) were developed to prevent tumor ingrowth, but stent migration is one of the problems with CSEMSs. Objective To evaluate a new, commercially available CSEMS flared ends and low axial force compared without anti-migration system high force. Design Multicenter, prospective study historical cohort. Setting Twenty Japanese referral centers. Patients This involved patients unresectable distal malignant biliary obstruction. Intervention Placement available, partially covered SEMS. Main Outcome Measurements Recurrent obstruction rate, time recurrent obstruction, stent-related complications, survival. Results Between April 2009 March 2010, 141 underwent nitinol placement, between May 2001 January 2007, 138 placement stainless as control. The silicone cover prevented ingrowth. There no significant differences in survival (229 vs 219 days; P = .250) or rate (33% 38%; .385) stents. Stent was less frequent (8% 17%; .019), significantly longer (373 285 .007) removal successful 26 27 (96%). Limitations Nonrandomized, controlled trial. Conclusion Partially an demonstrated ingrowth migration. (Clinical trial registration number: UMIN000002293.)