Self-expandable metallic versus plastic biliary stents in malignant biliary obstruction: A systematic review and meta-analysis.

Abstract

e16248 Background: Malignant biliary obstruction requires effective palliation with endoscopic stent placement and being the primary treatment modality, self expandable metallic stents and plastic stents are both used, however comparative efficacy stratified by obstruction location remained limited. The following systemic review and metanalysis aimed to compare outcomes of SEMS versus PS in patients with hilar and distant malignant bilary obstruction. Methods: A systematic literature search was conducted following PRISMA guidelines. Studies evaluating SEMS versus PS in MBO were included. Outcomes assessed were long term occlusion rate and 30-day mortality, 30-day occlusion rate, stent insertion success rate, therapeutic failure, reintervention rate, cholangitis, stent dysfunction, and stent exchange. Subgroup analyses were performed for hilar and distal obstruction. Pooled odds ratios (OR) and mean differences were calculated using random effects models. Heterogeneity was assessed using I² statistics. Results: For hilar obstruction, SEMS demonstrated significantly lower long-term occlusion rates compared to PS (OR 0.30; 95% CI 0.21–0.42; P0.00001; I² = 0%) and lower 30-day occlusion rates (OR 0.16; 95% CI 0.04–0.62; P = 0.008; I² = 0%). Therapeutic failure was significantly reduced with SEMS (OR 0.43; 95% CI 0.25–0.75; P = 0.003; I² = 0%), as was cholangitis (OR 0.39; 95% CI 0.18–0.88; P = 0.02; I² = 54%). No significant difference was observed in 30-day mortality (OR 0.62; 95% CI 0.30–1.31; P = 0.21; I² = 0%) or stent insertion success rate (OR 1.46; 95% CI 0.59–3.61; P = 0.41; I² = 21%). For distal obstruction, SEMS showed significantly lower long-term occlusion rates (OR 0.40; 95% CI 0.27–0.59; P0.00001; I² = 45%), 30-day occlusion rates (OR 0.36; 95% CI 0.16–0.83; P = 0.02; I² = 0%), therapeutic failure (OR 0.51; 95% CI 0.29–0.87; P = 0.01; I² = 0%), and cholangitis (OR 0.46; 95% CI 0.26–0.81; P = 0.007; I² = 20%). Stent dysfunction was significantly lower with SEMS (OR 0.28; 95% CI 0.17–0.47; P0.00001; I² = 0%). No significant differences were found in 30-day mortality (OR 0.85; 95% CI 0.46–1.58; P = 0.62; I² = 41%) or stent insertion success rate (OR 1.08; 95% CI 0.44–2.64; P = 0.87; I² = 11%). Conclusions: SEMS demonstrate superior stent patency with lower short term and long term occlusion rates compared to PS in both hilar and distal MBO. SEMS was found to be associated with reduced therapeutic failure, lower cholangitis rates, and decreased stent dysfunction, without significant differences in 30-day mortality or technical success. These findings support SEMS as the preferred first line endoscopic treatment for palliation of MBO regardless of obstruction location.