Endoscopic mucosal resection with precutting vs. anchoring technique using snare tip for 10–25 mm nonpedunculated colorectal polyps: a randomized controlled trial

BACKGROUND AND AIMS: Modified endoscopic mucosal resection (EMR) techniques using a snare tip, precutting EMR (P-EMR) and anchoring EMR (A-EMR), have been developed for the effective resection of nonpedunculated colorectal polyps measuring 10-25 mm. Although previous studies have compared either P-EMR or A-EMR with conventional EMR, no study has directly compared these two snare tip-assisted techniques within modified EMR. This study aimed to evaluate P-EMR and A-EMR in terms of the R0 resection rate and procedure duration. METHODS: This prospective randomized controlled trial enrolled patients with nonpedunculated colorectal polyps measuring 10-25 mm. The patients were randomly assigned to the P-EMR or A-EMR groups. The primary outcome was R0 resection rate, defined as en bloc resection with histologically tumor-free margins. Secondary outcomes included the injection-to-snaring time, total procedure time, and adverse events. RESULTS: Each group included 63 polyps, of which 126 were analyzed in the final evaluation. Both groups achieved high R0 resection rates (93.7% for P-EMR and 88.9% for A-EMR), with no significant difference (P = 0.344). However, the A-EMR group demonstrated significantly shorter injection-to-snaring time (181.8 ± 81.9 vs. 320.9 ± 143.5 s, P < 0.001) and total procedure time (259.7 ± 139.7 vs. 479.8 ± 249.0 s, P < 0.001). Adverse events, including intraprocedural and delayed bleeding, were comparable between the groups. CONCLUSION: Both P-EMR and A-EMR demonstrated high R0 resection rates for nonpedunculated polyps measuring 10-25 mm. However, A-EMR achieved these outcomes with a shorter procedure time than P-EMR.