Percutaneous metal stenting for malignant hilar biliary obstruction: a systematic review and meta-analysis of unilateral versus bilateral stenting

The purpose of this study is to assess the relative clinical efficacy of treating malignant hilar biliary obstruction (MHBO) via percutaneous unilateral or bilateral metal stenting. Relevant articles up to December 2019 were identified within the Web of science, Pubmed, Embase, and Cochrane Library databases. Stent dysfunction served as the primary endpoint, while we assessed technical success, clinical success, early and late complication incidence, and overall survival as secondary outcomes. Pooled odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated for dichotomous variables. Hazard ratio (HR) with 95% CI were determined for overall survival. This meta-analysis included seven studies. Six studies were non-randomized controlled trials (RCTs) and one study was a RCT. A total of 888 MHBO patients underwent either percutaneous unilateral (n = 376) or bilateral (n = 512) metal stenting in these seven studies. We detected no significant differences in stent dysfunction rates (OR 0.97; 95% CI 0.67, 1.41, P = 0.89), technical success rates (OR 1.10; 95% CI 0.53, 2.29, P = 0.81), clinical success rates (OR 0.72; 95% CI 0.43, 1.22, P = 0.22), early complication rates (OR 0.82; 95% CI 0.34, 1.98, P = 0.66), late complication rates (OR 0.87; 95% CI 0.29, 2.63, P = 0.81), or overall survival (HR: 0.99; 95% CI 0.83, 1.17, P = 0.88) between unilateral and bilateral groups. Funnel plots demonstrated no obvious publication bias of these primary and secondary endpoints. From a clinical perspective, percutaneous unilateral and bilateral metal stenting are similarly effective for treatment of patients with MHBO.