8-mm versus 10-mm diameter self-expandable metallic stent in bilateral endoscopic stent-in-stent deployment for malignant hilar biliary obstruction

Background We aimed to clarify the clinical benefits of using 8-mm versus 10-mm diameter self-expandable metallic stent (SEMS) in bilateral endoscopic stent-in-stent (SIS) deployment for malignant hilar biliary obstruction (MHBO). Methods A total of 72 consecutive patients with MHBO treated by endoscopic bilateral SIS deployment were enrolled. The 8-mm and 10-mm diameter SEMSs were used in 37 patients (8-mm group) and 35 patients (10-mm group), respectively. We retrospectively compared technical success, functional success, complications, successful re-intervention, time to recurrent biliary obstruction (RBO) and survival time between two groups. Results There were no significant inter-group differences in terms of technical success (8-mm vs. 10-mm group, both 100%), functional success (96% vs. 100%), early (5% vs. 9%) and late (19% vs. 14%) complications other than RBO, and successful endoscopic re-intervention (94% vs. 100%), respectively. Time to RBO (median: 198 days vs. 222 days; log-rank, P = 0.440) and survival time (median: 186 days vs. 235 days; log-rank, P = 0.883) did not differ significantly between the two groups. However, the success rate of endoscopic bilateral revisionary stent insertion for RBO was significantly higher in the 10-mm compared to the 8-mm group (68% vs. 31%; P = 0.044). Conclusions The 10-mm diameter SEMS is more suitable with regard to endoscopic re-intervention.