Uncovered Versus Fully-Covered Self-Expandable Metal Stents for the Management of Distal Malignant Biliary Obstruction.

BACKGROUND AND AIM: Self-expandable metal stents (SEMS) are widely used for palliation of distal malignant biliary obstruction (dMBO). However, previous studies comparing the outcomes between uncovered (UCSEMS) and covered (FCSEMS) stents report conflicting results. This large cohort study aimed to compare the clinical outcomes between UCSEMS and FCSEMS for dMBO.

METHODS: 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 included types of AEs, intervention-free stent patency, and the management and outcomes of stent occlusion.

RESULTS: The cohort included 454 patients (364 UCSEMS; 90 FCSEMS). Median follow-up duration was 9.6 months and was similar between the two groups. UCSEMS and FCSEMS had comparable clinical success (p=0.250). However, UCSEMS had significantly higher rates of AEs (33.5% vs 21.1%; p=0.023) and unplanned endoscopic reintervention (27.0% vs 11.1%; p=0.002). UCSEMS had a higher rate of stent occlusion (26.9% vs. 8.9%; p<0.001) and shorter median time to stent occlusion (4.4 vs 10.7 months; p=0.002). Stent reintervention free survival was higher in the FCSEMS group. FCSEMS had a significantly higher rate of stent migration (7.8% vs 1.1%; p<0.001), but similar rates of cholecystitis (0.3% vs 1.1%; p=0.872) and post-ERCP pancreatitis (6.3% vs 6.6%; p=0.90). When UCSEMS did occlude, placement of a coaxial plastic stent had a higher rate of stent re-occlusion compared to coaxial SEMS placement (46.7% vs 19.7%; p=0.007).

CONCLUSION: FCSEMS should be considered for the palliation of dMBO due to lower rates of AEs, longer patency rates, and lower rates of unplanned endoscopic intervention.