Self-expandable metal stents (SEMSs) are widely used for palliation of distal malignant biliary obstruction (dMBO). However, previous studies comparing the outcomes between uncovered SEMSs (UCSEMSs) and fully covered SEMSs (FCSEMSs) report conflicting results. This large cohort study aimed to compare the clinical outcomes between UCSEMSs and FCSEMSs for dMBO.

A retrospective cohort study was performed in patients with dMBO who underwent either UCSEMS or FCSEMS placement between May 2017 and May 2021. Primary outcomes were rates of clinical success, adverse events (AEs), and unplanned endoscopic reintervention. Secondary outcomes were types of AEs, intervention-free stent patency, and management and outcomes of stent occlusion.

The cohort included 454 patients (364 in the UCSEMS group and 90 in the FCSEMS group). Median follow-up duration was 9.6 months and was similar between the 2 groups. Use of UCSEMSs and FCSEMSs had comparable clinical success (P = .250). However, use of UCSEMSs had significantly higher rates of AEs (33.5% vs 21.1%; P = .023) and unplanned endoscopic reintervention (27.0% vs 11.1%; P = .002). UCSEMSs had a higher rate of stent occlusion (26.9% vs 8.9%; P < .001) and shorter median time to stent occlusion (4.4 months vs 10.7 months; P = .002). Stent reintervention–free survival was higher in the FCSEMS group. FCSEMSs had a significantly higher rate of stent migration (7.8% vs 1.1%; P < .001), but patients in the FCSEMS group had similar rates of cholecystitis (.3% vs 1.1%; P = .872) and post-ERCP pancreatitis (6.3% vs 6.6%; P = .90). When UCSEMSs did occlude, placement of a coaxial plastic stent had a higher rate of stent reocclusion compared with coaxial SEMS placement (46.7% vs 19.7%; P = .007).

FCSEMSs should be considered for the palliation of dMBO because of lower rates of AEs, longer patency rates, and lower rates of unplanned endoscopic intervention.