BACKGROUND: To evaluate the safety and efficacy of biliary metallic stent (BMS) combined with radioactive METHOD: From January 2016 to January 2022, 317 patients with MHO underwent percutaneous trans-hepatic biliary drainage at our center. Among them, 40 patients underwent BMS combined with RISS treatment (experimental group), and 52 patients underwent BMS alone (control group). Primary endpoints were technical success, complications and stent patency time (SPT). Secondary endpoints were clinical success and overall survival (OS). RESULTS: The technical success (100% vs. 100%) and clinical success rate (92.50% vs. 90.04%) showed no statistically significance between the experimental and control groups (P >
0.05). The Grade 3-5 early and late complications showed no significance between both groups (P >
0.05). The SPT [(8.2 ± 0.39) vs. (5.8 ± 0.33) months] and OS [(13.6 ± 0.81) vs. (11.7 ± 0.44) months)] of the experimental group showed significantly longer than that of the control group ((P <
0.05). Multivariate analysis revealed higher Bismuth type as an independent predictor for shorter OS (HR: 1.846, 95% CI: 1.019-3.341, P = 0.043) and SPT (HR: 1.959, 95% CI: 1.269-4.420, P = 0.009). CONCLUSION: Biliary metallic stent (BMS) placement combined with radioactive iodine-125 seed strands (RISS) is a safe and effective treatment option for patients with malignant hilar obstruction (MHO). However, multicenter randomized controlled trials are required to further validate the effectiveness and long-term benefits of this therapeutic approach.