Anchoring-endoscopic mucosal resection vs. conventional endoscopic mucosal resection for large (10-25 mm) colorectal polyps

Background and Aims: Colorectal polyps greater than 10 mm in size are often incompletely resected. Anchoring-endoscopic mucosal resection (A-EMR) is the technique of making a small incision at the oral side of the polyp using a snare tip after submucosal injection to avoid slippage during ensnaring. This study was performed to evaluate whether A-EMR could increase the complete resection rate for large colorectal polyps compared to conventional endoscopic mucosal resection (C-EMR). Methods: Polyps with sizes of 10–25 mm were randomly allocated to either the A-EMR group or the C-EMR group. Results: A total of 105 and 106 polyps were resected using A-EMR or C-EMR, respectively. In the intention-to-treat population, the complete resection rate was 89.5% in the A-EMR group and 74.5% in the C-EMR group (relative risk [RR], 1.20; 95% confidence interval [CI], 1.04–1.38; P=0.011). En bloc resection rate for the A-EMR and C-EMR group was 92.4% vs 76.4% (RR, 1.21; 95% CI, 1.06–1.37; P=0.005) and R0 resection rate was 77.1% vs 64.2% (RR, 1.18; 95% CI, 0.98–1.42; P=0.074), respectively. The total procedure time was 3.2 minutes (IQR, 2.6–4.1) in the A-EMR group and 3.0 minutes (IQR, 2.2–4.6) in the C-EMR group (median difference, 0.2; 95% CI, -0.22–0.73; P =0.250). There was a delayed bleeding and a perforation in C-EMR group, respectively. Conclusions: A-EMR was superior to C-EMR for the complete resection of large colorectal polyps. A-EMR can be considered one of the standard methods for the removal of colorectal polyps with sizes of 10 mm or greater.