Transmural side holes in covered metal stents do not reduce bile duct occlusion or cholecystitis: a single center study

Background and Study Aims Fully covered, self-expandable metal stents (FCSEMS) are used to treat biliary strictures. FCSEMS with transmural side holes may facilitate cystic duct drainage to mitigate risk of cholecystitis and impact other stent-related adverse events such as migration and occlusion. This study compared rates of premature stent occlusion and acute cholecystitis among patients with biliary strictures who underwent first-time placement of a FCSEMS with or without transmural side holes. Patient and Methods This was a retrospective cohort study of adults who underwent endoscopic retrograde cholangiopancreatography (ERCP) with FCSEMS between April 2022 to April 2025 for malignant or benign extrahepatic bile duct strictures. The primary outcome was premature bile duct occlusion. The secondary outcome was acute cholecystitis among patients with an intact gallbladder. Results Among 219 patients meeting enrollment criteria, 57 (26%) had side holes. The rate of premature stent occlusion was similar with transmural side holes (12%) vs. without (11%, HR 1.02, 95% CI 0.42-2.43, p = 0.96). Among patients with an intact gallbladder (n=129), acute cholecystitis rates were similar with side holes (6%) or without (4.8%, HR 1.01, 95% CI 0.22-4.5, p = 0.99). Conclusions In this preliminary single center retrospective study, FCSEMS stents with side holes did not reduce rates of premature bile duct stent occlusion or acute cholecystitis compared to FCSEMS without side holes.