Unilateral versus bilateral Y-type stent-in-stent metal stent insertions in inoperable malignant hilar biliary strictures: A multicenter retrospective study

Background: To date, there is controversy regarding unilateral versus bilateral stent placement in patients with malignant hilar biliary strictures(MHBSs). The aim of this study was to compare the clinical outcomes and complications of unilateral and bilateral(stent-in-stent method) stent placements for these patients. Methods: We conducted a multicenter retrospective analysis of patients with inoperable MHBS who underwent endoscopic self-expandable metal stent(SEMS) placement from January 2009 to December 2019. Two groups classified according to the stent procedure method were compared for demographic, procedural, and postprocedure factors. Survival analysis for patency loss and overall survival was also conducted. Results: A total of 236 subjects were included. A superior technical success rate was found in the unilateral stent group(98.8% vs. 82.5%, P < 0.001), whereas the clinical success rate was higher in the bilateral group(85.7% vs. 70.5%, P = 0.028). There was no significant difference with respect to complications or patency loss, and the bilateral group had better overall survival( P < 0.01). In the Cox proportional hazard model, MHBSs from lymph node compression were associated with a higher risk of death(HR = 9.803, P = 0.003). In contrast, bilateral SEMS insertion showed reduced postprocedural mortality(HR = 0.316, P = 0.001). Conclusions: Y-type stent-in-stent bilateral SEMSs are technically difficult but demonstrated more favorable overall survival for palliative bile drainage of inoperable MHBS patients compared to unilateral insertions.