Comparison of fully covered versus uncovered self-expandable metallic stents in treating inoperable malignant distal biliary obstruction: a retrospective study.

Background: The optimal choice between fully covered self-expandable metallic stents (FCSEMSs) and uncovered self-expandable metallic stent (USEMS) for managing inoperable malignant distal biliary obstruction (MDBO) remains debatable. This study aims to compare the efficacy of CSEMS and USEMS in patients with MDBO.

Method: A retrospective analysis was conducted with inoperable MDBO between January 2017 to December 2021 who underwent either USEMS or FCSEMS implantations via endoscopic retrograde cholangiopancreatography (ERCP). Primary outcomes were overall survival and stent patency. Secondary outcomes were stent occlusion rates and postoperative complications.

Results: This study included 310 patients (235 patients received FCSEMS implantations and 75 received USEMS implantations). Median follow-up duration was 5.2 months. No significant difference was observed in overall survival between the FCSEMS and USEMS groups (167 vs 169 days, p = 0.566). The mean stent patency duration was longer in the FCSEMS group compared to the USEMS group (445 vs 348 days, p = 0.020). There were no significant differences in postoperative complications between the two groups. Multivariate analysis indicated that endoscopic sphincterotomy (EST) (HR = 1.259, 95% CI: 1.167-1.358, p < 0.001), USEMS (HR = 2.277, 95% CI: 1.750-2.963, p < 0.001), stent length (HR = 1.804, 95% CI: 1.662-1.959, p < 0.001), preoperative biliary stent (HR = 1.166, 95% CI: 1.070-1.271, p < 0.001) and non-pancreatic cancer (HR = 1.404, 95% CI: 1.299-1.516, p < 0.001) were independent risk factors for stent occlusion, while BMI ⩾ 24 kg/m² (HR = 0.600, 95% CI: 0.548-0.657, p < 0.001) was identified as a protective factor. In the subgroup analysis for pancreatic cancer, patients with FCSEMS (n = 109) had an average survival time of 154.14 ± 93.93 days, while those with USEMS (n = 34) had an average survival time of 130.32 ± 57.31 days (p = 0.21). For non-pancreatic cancer, patients with FCSEMS (n = 115) had an average survival time of 194.10 ± 93.40 days, and patients with USEMS (n = 34) had an average survival time of 204.97 ± 93.40 days (p = 0.67).

Conclusion: Compared to USEMS, FCSEMS provides a longer stent patency duration for patients with MDBO. However, no significant differences were found in overall survival and postoperative complications in this retrospective study.