Endoscopic Mucosal Resection after Circumferential Mucosal Incision of Large Colorectal Tumors: Comparison With Endoscopic Submucosal Dissection

Background: Endoscopic mucosal resection is widely used for treating superficial colorectal carcinomas or premalignant colorectal tumors. Piecemeal resection and local recurrence are frequent with endoscopic mucosal resection for >20-mm-diameter tumors. Endoscopic submucosal dissection, which facilitates en bloc resection of large colorectal tumors, is useful for superficial colorectal tumors. In our hospital, endoscopic mucosal resection after circumferential mucosal incision was used for colorectal tumorswith a diameter of 20?30 mm. Objective: To determine the efficacy and safety of endoscopic mucosal resection after circumferential mucosal incision. Design: Retrospective clinical trial at a single center Settings: ShigaUniversity of Medical Science Patients: 77 colorectal tumors (69 patients) with a diameter of 20?30 mmendoscopically treated between January 2010 and May2012 at Shiga University of Medical Science. Interventions: Endoscopic submucosal dissection and endoscopic mucosal resection after circumferential mucosal incision. Main Outcome Measures: En bloc resection rate, procedure time, complications Results: ESD was associated with longer procedure times compared with C-EMR (p < 0.005). En bloc resection, complete curative resection, and perforation rates were similar in both groups Delayed bleeding was limited to the ESD group (2.1%).Histopathological analysis revealed that the incidence of adenoma was lower in the ESD group than in the C-EMR group(p= 0). Mucosal cancer was more frequent in the ESD group(p= 0). The nonlifting sign was seen in 16.7% patients with laterally spreading tumors of nongranular type in the en blocCEMR group and 100% patients with laterally spreading tumors of nongranular type in the piecemeal C-EMR group (p = 0.035). Limitations: A single-centerretrospective study Conclusions: C-EMRand ESD were equally effective for treating colorectal tumors with a diameter of 20?30 mm.