Value of endoscopic submucosal dissection treating flat rectal precancer or cancer in-situ lesions        ZHONG Yun-shi, YAO Li-qing, XU Jian-min, et al. Endoscopic Center, Zhongshan Hospital, Fudan University; Endoscopic Research Institute, Fudan University, Shanghai 200032, China
Corresponding author：YAO Li-qing，E-mail：yao.liqing@zs-hospital.sh.cn
Abstract    Objective    To assess the value of endoscopic submucosal dissection treating flat rectal precancer or cancer in-situ lesions. Methods    Eighty-three patients with flat rectal precancer or cancer in-situ leisions were treated with ESD from November 2006 to March 2011 in the Endoscopic center, Zhongshan Hospital of Fudan University. Complications and relapse rate were analyzed. Results    Fifty-two patients were located in lower rectum (lower than 7cm from anal), 18 in the middle rectum (7-12cm from anal) and 13 in higher rectum (13-18cm from anal). All the patients received ESD successfully. The median operating time was 42（15-129）min and median blood loss was 50（5-400）mL. Mean diameter of the lesions was 2.29±3.11（1.6-8.5）cm. En-bloc resection rate was 85.5%（71/83）. The main complications included perforation in 12 (14.5%) patients, bleeding during the operation in 11 (13.3%) patients and  delayed bleeding in 6(7.2%) patients. All 83 patients were followed up with the mean follow-up time of 3-31（15±6）months and no recurrence occurred. Conclusion    ESD is an effective, safe, minimal invasive method to deal with flat rectal precancer or cancer in-situ leisions.