Efficacy and Safety of Multihole Partially Covered Self-Expandable Metal Stents for Distal Malignant Biliary Obstruction: A Single-Center Retrospective Study.

Background: Covered self-expandable metal stents (SEMS) are the standard for managing unresectable distal malignant biliary obstruction (DMBO), as they prolong the time to recurrent biliary obstruction (TRBO). However, fully covered SEMS (FCSEMS) increases the risk of cholecystitis and pancreatitis. This exploratory study evaluated a novel multihole partially covered SEMS (MHSEMS) designed to reduce these risks. Methods: The clinical data of 26 DMBO patients treated with MHSEMSs were retrospectively compared with those of 63 patients treated with FCSEMSs between April 2018 and October 2024. The outcomes included clinical success, early complications, and recurrent biliary obstruction (RBO). Results: The baseline characteristics, including age (median 78 years), sex distribution (55.2% vs. 57.7% male), BMI (20.5 vs. 19.8), tumor size (27 mm vs. 30 mm), and stricture length (20 mm vs. 19.5 mm), were comparable between the groups. Procedural factors, including initial papillary cannulation (34.9% vs. 26.9%) and pancreatography (12.9% vs. 15.4%), were also similar in terms of incidence. Early complications were less common in the MHSEMS group (7.7% vs. 23.8%), with no cases of cholecystitis observed. Fewer early complications were observed with MHSEMS, suggesting potential clinical benefits. The RBO rates (7.7% vs. 15.9%, Conclusion: Although the differences in outcomes were not statistically significant, the incidence of early complications was lower, especially for cholecystitis, with the MHSEMS in the management of DMBO. Larger prospective studies are needed to confirm these preliminary findings.