Preliminary Lesion Molding-Aided Endoscopic Mucosal Resection Versus Conventional Endoscopic Mucosal Resection for Nonpedunculated Colorectal Lesions

BACKGROUND: En bloc and R0 resection of nonpedunculated colonic lesions by conventional endoscopic mucosal resection (EMR) are challenging. Preliminary lesion molding-aided EMR (PM-EMR) is useful for reducing snaring slippage, which may increase successful en bloc and R0 resection rates. Herein, we compared PM-EMR and conventional EMR outcomes. METHODS: Overall, 112 patients with nonpedunculated colonic lesions measuring 8-15 mm were randomly allocated to either the PM-EMR group or the conventional EMR group. Baseline characteristics and treatment results were analyzed between the groups. RESULTS: En bloc resection and R0 resection were achieved in the PM-EMR group (100%, 94.6%) and the conventional EMR group (76.8%, 67.9%). For lesions ≥ 10 mm, en bloc and R0 resection rates were greater for PM-EMR than for conventional EMR (100.0% versus 74.4%; 94.4% versus 62.8%, respectively). For lesions with macroscopic morphologies indicating Is/IIa located in the left/right colon, PM-EMR was significantly better than conventional EMR for en bloc resection (100.0% versus 69.2%, 100% versus 76.5%; 100.0% versus 75.0%, 100.0% versus 68.2%, respectively) and R0 resection (100.0% versus 65.4%, 88.9% versus 52.9%; 100.0% versus 60.0%, 90.0% versus 63.6%, respectively). CONCLUSIONS: PM-EMR is significantly better than conventional EMR regarding en bloc and R0 resection of 10-15 mm nonpedunculated colorectal lesions.