Underwater vs Traction-assisted ESD in Colorectal Lesions 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 using saline (UW-ESD) 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 (NMA) of randomized controlled trials (RCTs) 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 (SMD) with 95% confidence intervals (CI).

Results: Four RCTs including 543 ESD (98 UW-ESD, 171 T-ESD, 274 C-ESD) 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 to 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).

Conclusion: UW-ESD and T-ESD are both effective and safe strategies for colorectal lesions resection; however, UW-ESD is the only technique that has demonstrated superior dissection speed.