Background: Endoscopic biliary stent drainage is effective in the palliative treatment of patients with hilar cholangiocarcinoma (HCA). However, no randomized controlled trial comparing the efficacy of the self-expandable metal stent (SEMS) and the plastic stent (PS) in patients with unresectable complex HCA is available.

Objective: To compare the successful drainage rates of endoscopic SEMSs and PSs.

Design: A single-center, open-label randomized controlled trial.

Setting: University hospital in KhonKaen, Thailand.

Patients: One hundred eight patients with unresectable complex, Bismuth type II-IV HCA.

Interventions Endoscopic retrograde cholangiography with unilateral SEMS or PS insertion.

Main Outcome Measurements Successful drainage rate.

Limitations: Diagnosis of HCA was made by clinical presentations, imaging studies, and clinical outcome during follow-up.

Results: One hundred eight patients were randomly allocated to the SEMS and PS groups. Intention-to-treat analysis revealed that the successful drainage rate in the SEMS group was higher than in the PS group (70.4% vs 46.3%, P = .011). The median survival times were 126 and 49 days, respectively, in the SEMS and PS groups. The overall survival rates of the patients in both groups were statistically different by log-rank test (P = .002).

Conclusions: Endoscopic biliary drainage with the SEMS provides better adequacy of drainage and longer survival compared with the PS in patients with unresectable complex HCA.