Clinical outcomes of plastic versus self-expanding metal stents in malignant hilar biliary obstruction

BACKGROUND: Malignant hilar biliary obstruction (MHBO) is a challenging condition with a poor prognosis, often requiring palliative biliary drainage. Endoscopic placement of plastic stents (PS) or self-expanding metal stents (SEMS) are the preferred approaches, but the optimal choice remains under debate. This study compares the clinical outcomes, patency, and survival associated with PS and SEMS in patients with unresectable MHBO. METHODS: This retrospective study analyzed patients with MHBO who underwent endoscopic drainage between January 2015 and December 2022 at a tertiary cancer center. Clinical success, stent patency, survival, and reintervention rates were compared between patients receiving PS or SEMS. Cox proportional hazards models and Kaplan-Meier survival analyses were used to evaluate outcomes. RESULTS: A total of 86 patients were included, with 39 (45.3%) receiving SEMS and 47 (54.7%) receiving PS. Clinical success was higher in the SEMS group (76.9% vs. 51.1%; p = 0.015), but this association was not confirmed in multivariate analysis. SEMS demonstrated significantly longer patency (median 213 vs. 78 days; p = 0.01) and a lower risk of recurrent biliary obstruction (HR 3.17, 95% CI 1.60-6.27; p = 0.001). However, overall survival did not differ significantly between groups (p = 0.059). Multivariate analysis identified better ECOG status (0-2) and bilirubin levels < 10 mg/dL as independent predictors of clinical success and longer survival. CONCLUSION: SEMS provide superior patency compared to PS but did not significantly impact overall survival. Clinical success was influenced by ECOG performance status and baseline bilirubin levels rather than stent type alone.