Underwater versus traction-assisted endoscopic submucosal dissection for colorectal lesions: a network meta-analysis of randomized controlled trials

Background and aims: Among the newly established endoscopic submucosal dissection (ESD) techniques, underwater ESD (UW-ESD) using saline solution and traction-assisted ESD (T-ESD) aim to address the limitations of conventional ESD (C-ESD) for the resection of colorectal lesions. However, their comparative efficacy and safety remain uncertain. Methods: A systematic review and network meta-analysis of randomized controlled trials was conducted to compare UW-ESD and T-ESD. Main outcomes included R0 resection, dissection speed, and adverse events (AEs). We conducted indirect comparisons between UW-ESD and T-ESD and direct comparisons with C-ESD. Results were presented as risk ratios (RR) and standard mean deviations (SMDs) with 95% confidence intervals (CIs). Results: Four RCTs including 543 ESDs (98 UW-ESDs, 171 T-ESDs, and 274 C-ESDs) were analyzed. For R0 resection, no significant difference was observed between UW-ESD and T-ESD (RR = 0.99; 95% CI, 0.92-1.07), and both were comparable to C-ESD (UW-ESD: RR = 1.02; 95% CI, 0.98-1.07; T-ESD: RR = 1.01; 95% CI, 0.96-1.07). Dissection speed was significantly higher with UW-ESD compared with both T-ESD (SMD = 0.36; 95% CI, 0.14-0.87) and C-ESD (SMD = 0.54; 95% CI, 0.15-0.92). No significant difference in AEs was observed between UW-ESD and T-ESD (RR = 1.80; 95% CI, 0.14-23.16), and both were comparable to C-ESD (UW-ESD: RR = 0.48; 95% CI, 0.06-4.15; T-ESD: RR = 0.86; 95% CI, 0.22-3.37). Conclusions: UW-ESD and T-ESD are both effective and safe strategies for colorectal lesion resection; however, UW-ESD is the only technique that has demonstrated superior dissection speed.