Clinical Outcomes of Multi-Hole Covered Self-Expandable Metal Stents for Malignant Distal Biliary Obstruction: A Retrospective Comparative Study With an Exploratory Evaluation of 6-mm Devices.

OBJECTIVES

Covered self-expandable metal stents (CSEMS) are widely used for malignant distal biliary obstruction (MDBO), but cholecystitis, post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP), stent migration, and recurrent biliary obstruction (RBO) remain clinically important limitations. Multi-hole SEMS (MHSEMS) is a novel CSEMS designed to preserve side-branch drainage and reduce migration. We evaluated MHSEMS compared with conventional CSEMS and explored the potential impact of a newly available 6-mm MHSEMS.

METHODS

This retrospective single-center study included consecutive patients who underwent initial transpapillary SEMS placement for MDBO between September 2015 and December 2025. Study-I compared MHSEMS versus conventional CSEMS limited to 8-10 mm diameter stents. Study-II included MHSEMS cases only and compared 6-mm versus 8-10 mm MHSEMS. Outcomes included cholecystitis, PEP, RBO, time to RBO (TRBO), and RBO causes.

RESULTS

Study-I included 148 patients; median follow-up was 80.5 versus 81.5 days (p = 0.761). Overall cholecystitis was 1/34 versus 23/98 (p = 0.008). MHSEMS was independently protective for cholecystitis (odds ratio [OR] 0.0879; 95% confidence interval [95%CI] 0.0111-0.696), whereas cystic duct involvement increased risk (OR 3.190; 95%CI 1.160-8.720). PEP was 4/36 versus 18/112 (p = 0.595). RBO was 1/36 versus 28/112, including migration in 0 versus 9. TRBO was longer with MHSEMS (log-rank p = 0.023). Study-II included 64 MHSEMS cases; PEP was 1/28 versus 4/36 (p = 0.375), RBO was 1/28 versus 1/36, and no migration occurred.

CONCLUSIONS

MHSEMS was associated with fewer cholecystitis events and migration and longer TRBO versus conventional CSEMS. The potential benefit of 6-mm MHSEMS for reducing PEP remains exploratory and requires confirmation in longer prospective studies.