Background: Endoscopic submucosal dissection (ESD) is accepted as a minimally invasive treatment for early gastric cancer; however, it is not widely used in the colorectum because of its technical difficulty. Objective: To determine the feasibility of using ESD for treating large superficial colorectal tumors and to evaluate the clinical outcome. Design and Setting: Case series conducted at the National Cancer Center Hospital in Tokyo. Patients: A total of 198 consecutive patients were treated for 200 lesions. Interventions: Procedures were performed, before July 2004, by using a monopolar needle knife or an insulation-tipped knife (IT knife). After July 2004, the procedures were performed by using a bipolar needle knife or an IT knife. After injection of glycerol and sodium hyaluronate acid into the submucosal (sm) layer, a circumferential incision was made and sm dissection was performed endoscopically. Main Outcome Measurements: The en bloc resection rate was 84% and the curative resection rate was 83%. Results: Among the 200 ESDs, 51 involved tubular adenomas, 99 intramucosal cancers, 22 minute sm cancers, and 28 sm deep cancers. The median operation time was 90 minutes, and the mean size of resected specimens was 38 mm (range, 20-150 mm). Perforations occurred in 10 cases (5%) and postoperative bleeding in 4 cases (2%), but only 1 perforation case needed emergency surgery, because endoscopic clipping was ineffective. Limitations: No long-term outcome data yet. Conclusions: ESD is a feasible technique for treating large superficial colorectal tumors, because it provides a higher en bloc resection rate and is less invasive than surgical resection.
