Thermal ablation of margins for recurrence prevention after endoscopic mucosal resection: a systematic review and meta-analysis

Background and aims Endoscopic mucosal resection (EMR) of large colorectal lesions can be challenging, and residual lesions after EMR can progress to colorectal cancer. We aimed to assess the efficacy and safety of adding thermal ablation of margins [using argon plasma coagulation (APC) or snare tip soft coagulation (STSC)] in reducing recurrence rates after EMR. Methods We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) identified from PubMed, Cochrane Library, and Embase. The primary outcome was the recurrence rate. Secondary outcomes were overall adverse events (AEs) and delayed bleeding. We pre-specified subgroup analyses by lesion size, thermal ablation technique, and resection type. The random-effects model was used to calculate the pooled risk ratio (RR) with 95% confidence interval (CI). Heterogeneity was assessed using the Cochran's Q test and I2 statistics. Results We included four RCTs (815 patients and 872 colorectal lesions). Thermal ablation reduced recurrence rates [RR 0.31; 95%CI (0.20-0.47); I2 = 0%], while the risk of overall AEs [RR 0.93; 95%CI (0.73-1.17); I2 = 0%] was similar between both groups. The results were consistent in subgroup analyses of APC, STSC, polyps > 20 mm, and piece-meal resection. Conclusion Thermal ablation of margins following EMR reduced recurrence rates while maintaining a comparable safety profile.