Uncovered versus fully covered self-expandable metal stents for nonpancreatic cancer: A propensity score-matched, multicenter study

Background: The efficacy of uncovered self-expandable metal stents (UCSEMS) compared to that of fully covered self-expandable metal stents (FCSEMS) for distal malignant biliary obstruction (dMBO) is controversial. Studies have highlighted the heterogeneity of disease conditions because pancreatic and nonpancreatic cancers exhibit different clinical courses. This is the first study to specifically compare the safety and efficacy of UCSEMS and FCSEMS for dMBO caused by nonpancreatic cancer. Methods: This retrospective multicenter study included patients who underwent UCSEMS or FCSEMS placement for nonpancreatic cancer-induced dMBO at four centers between January 2010 and April 2024. Propensity score matching (1:1) of both groups was performed. Technical and clinical success, adverse events, recurrent biliary obstruction (RBO), time to RBO (TRBO), and overall survival (OS) of these groups were compared. Results: After propensity score matching, 24 patients were included in each group. Technical and clinical success rates and TRBO did not differ significantly between the groups (median TRBO: 311 days [UCSEMS] vs 317 days [FCSEMS]; P=0.42). Similarly, OS was not significantly different (median OS: 432 days [UCSEMS] vs 190 days [FCSEMS]; P=0.083). The postendoscopic retrograde cholangiopancreatography pancreatitis incidence of the UCSEMS group was significantly lower than that of the FCSEMS group (4.2% vs. 33%; P=0.023). Conclusions: UCSEMS may be safer than FCSEMS for managing dMBO caused by nonpancreatic cancer.