Comparison of Uncovered and Covered Biliary SEMS for the Salvage of Obstructed SEMS: A Multicenter Retrospective Propensity Score-Weighted Study.

BACKGROUND AND AIMS: Recurrent biliary obstruction (RBO) is common after uncovered self-expandable metal stent (UCSEMS) placement in unresectable distal malignant biliary obstruction. We compared stent patency, clinical outcomes, and RBO patterns between fully covered (FCSEMSs) and uncovered SEMSs (UCSEMSs) used as secondary stents after initial UCSEMS failure. METHODS: This multicenter retrospective study included 96 patients who underwent secondary SEMS placement for RBO (51 FCSEMSs, 45 UCSEMSs). Inverse probability of treatment weighting was applied. The primary outcome was stent patency; secondary outcomes included clinical success, adverse events (AEs), causes of RBO, and overall survival (OS). RESULTS: After adjustment, median stent patency was comparable between FCSEMSs and UCSEMSs (145 vs. 188 days; p = 0.435). Clinical success (92.2% vs. 98.2%; p = 0.146) and AE rates (12.2% vs. 6.0%; p = 0.323) were also similar. Tumor ingrowth was more common in the UCSEMS group, whereas sludge or food impaction was the predominant cause of RBO in the FCSEMS group. CONCLUSIONS: FCSEMSs and UCSEMSs showed comparable clinical outcomes as secondary stents after initial UCSEMS failure. While overall outcomes were similar, RBO patterns differed by stent type, with tumor ingrowth more frequent in UCSEMSs and sludge impaction or tumor overgrowth in FCSEMSs.