Retrospective evaluation of slim fully covered self-expandable metallic stent for unresectable malignant hilar biliary obstruction

Background There have been few reports of covered self-expandable metallic stent (SEMS) placement for malignant hilar-biliary obstruction (MHBO) because of risk of biliary branch obstruction. We studied feasibility and efficacy of 6-mm-diameter, slim, fully covered SEMS (SFCSEMS) in a relatively large cohort. Methods We retrospectively evaluated SFCSEMS in unresectable MHBO from December 2016 to September 2021 in Juntendo University Hospital. Results We enrolled consecutive 54 unresectable MHBO (18 bile duct, 11 gallbladder, eight pancreatic, two hepatocellular, and 15 metastatic cancer cases) including Bismuth-type II (n = 11), III (n = 17), and IV (n = 26), and placed two (n = 35) or three (n = 19) SFCSEMS. The technical and clinical success rate was 100% and 92.5%, respectively, with 76.3 min of mean procedure time. Recurrent biliary obstruction (RBO) was observed in 35.2% and the median cumulative time to RBO (TRBO) was 181 days. Other adverse events were 11.1% (four mild-pancreatitis, one segmental-cholangitis, and one cholecystitis). There were no failed cases of stent exchange and second SFCSEMS (n = 6) showed significantly lower RBO (16.7% vs. 81.8%, P = .0364) and longer TRBO (undefined vs 86 days; P = .0617) than plastic stent (n = 11). Conclusions Endoscopic placement of SFCSEMS for unresectable MHBO was effective and feasible with low incidence of segmental cholangitis, and exchange strategy of SFCSEMS was promising.