Comparison of cold snare endoscopic mucosal resection and hot snare endoscopic mucosal resection for small colorectal polyps: a randomized controlled trial

Incomplete resection rates vary among endoscopists performing cold snare polypectomy. Cold snare endoscopic mucosal resection (CS-EMR) is the technique of cold resection after submucosal injection to reduce incomplete resection. This study aimed to evaluate the efficacy and safety of CS-EMR for small colorectal polyps compared to hot snare endoscopic mucosal resection (HS-EMR). Preplanned sample size required 70 polyps to CS-EMR group or HS-EMR group, respectively. Patients with polyps sized 6-9 mm were randomly allocated to either the CS-EMR or the HS-EMR group. The primary outcome was residual or recurrent adenoma (RAA) rate. A total of 70 and 68 polyps were resected using CS-EMR and HS-EMR, respectively. In the intention-to-treat population, the RAA rate was 0% in the CS-EMR group and 1.5% in the HS-EMR group (risk difference [RD], - 1.47; 95% confidence interval [CI] - 4.34 to 1.39). En bloc resection rate was 98.6% and 98.5% (RD, - 0.04; 95% CI - 4.12 to 4.02); the R0 resection rate was 55.7% and 82.4% (RD, - 27.80; 95% CI - 42.50 to - 13.10). The total procedure time was 172 s (IQR, 158-189) in the CS-EMR group and 186 s (IQR, 147-216) in the HS-EMR group (median difference, - 14; 95% CI - 32 to 2). Delayed bleeding was 2.9% vs 1.5% (RD, 1.37; 95% CI - 3.47 to 6.21) in both groups, respectively. CS-EMR was non-inferior to HS-EMR for the treatment of small colorectal polyps. CS-EMR can be considered one of the standard methods for the removal of colorectal polyps sized 6-9 mm.