Comparative Effectiveness of Lumen-Apposing Metal Stents and Plastic Stents for the Treatment of Pancreatic Walled-Off Necrosis: A Meta-analysis

Background: Plastic stents (PS), lumen-apposing metal stents (LAMS) and biflanged metal stents (BFMS) are used for initial drainage of pancreatic walled-off necrosis (WON). There are no strong evidence to support the use of LAMS/BFMS over PS, and prior systematic reviews lack comparative analyses and also lack both trial data and observational studies for WON efficacy outcomes. The aim of this study is to compare the efficacy and adverse events (AEs) in LAMS/BFMS versus PS in patients with pancreatic WON. Methods: A comprehensive search up to December 1, 2020, was performed. The primary outcome was clinical improvement after drainage. Secondary outcomes included AEs and technical failure. Pooled odds ratios (OR) with 95% confidence intervals (CI) were reported using random effects models. Heterogeneity was evaluated with the Cochrane I ² statistic. Subgroup and sensitivity analyses were performed. The quality of the evidence was assessed using Grading of Recommendations, Assessment, Development and Evaluations (GRADE). Results: Nine studies (one randomized controlled trial and eight observational) were included for the primary outcome including 493 patients treated with LAMS/BFMS and 514 with PS. LAMS/BFMS were associated with higher odds of clinical improvement compared with PS (OR 2.58; 95% CI 1.81, 3.68; I ² = 1%). This association remained robust in sensitivity analyses. The use of LAMS/BFMS was not associated with higher AEs (OR 1.22; 0.61, 2.46; I ² = 71%). There was no difference in technical failure (OR 1.06; 0.19, 6.00; I ² = 12%). Conclusions: LAMS/BFMS seem to result in better clinical outcomes compared with PS in patients with pancreatic WON, with comparable AEs and technical failure. Larger randomized controlled trials for this comparison are warranted.