PurposeThe purpose of this study was to compare the safety and effectiveness of a self-expandable metallic stent (SEMs) with a novel brachytherapy biliary drainage catheter (BBDC, double 125I seeds strands) or a single 125I seeds strand in the treatment of advanced perihilar cholangiocarcinoma (pCCA) with malignant obstructive jaundice (MOJ).MethodsFrom September 2016 to December 2018, we retrospectively enrolled patients with biliary stent implantation after receiving either BBDC loaded with 125I seeds (double-strands irradiation group) or an 125I seed strand treatment (single-strand irradiation group, control group). The outcomes were analyzed regarding the relief of obstructive jaundice, and interventional-related complications. Moreover, the Kaplan–Meier method was used to analyze stent patency and survival.ResultsThe success rate of interventional therapy in both groups was 100%, and all patients with MOJ were alleviated. According to the Common Terminology Criteria for Adverse Events (CTCAE 4.02), the grade 3 or 4 complications in the BBDC group and in the control group were 6/34 (17.65%) and 7/39 (17.95%), respectively (P > 0.05). The median and mean overall stent patency of the BBDC group and the control group were 207 days versus 180 days, 204.212 days versus 186.278 days (P = 0.043). The median and mean overall survivals in the BBDC group were higher than those in the control group (245 days versus 212 days, 244.883 days versus 221.844 days, P = 0.030).ConclusionThis interim analysis showed that BBDC (double-stranded irradiation) can prolong the stent patency time compared with 125I seed strand treatment (single-stranded irradiation) and had the advantage of reducing jaundice, which seemed to extend the survival period of advanced pCCA.