RISK MANAGEMENT OF THERAPEUTIC COLONOSCOPY (HOT BIOPSY,POLYPECTOMY, ENDOSCOPIC MUCOSAL RESECTION AND ENDOSCOPIC SUBMUCOSAL DISSECTION)

The concept of an adenoma–carcinoma sequence has been widely accepted in the colon and rectum, contrary to that in gastric cancer. Consequently, most target lesions for endoscopic resection using these newly developed techniques are histologically assessed as adenoma or intramucosal carcinoma in adenoma. Based on results in conventional endoscopic mucosal resection (EMR), almost all remnant or recurrent tumors can be successfully managed by salvage EMR, and all materials resected by salvage EMR also showed adenoma or intramucosal cancer. These results suggest that en bloc resection is not always clinically necessary to obtain complete cure for all colorectal neoplasia. However, larger lesions tend to be resected in a piecemeal fashion; it is difficult to confirm whether EMR has been completed or not. For precise histopathological assessment of the resected specimen, endoscopic submucosal dissection (ESD) for en bloc resection is desirable, although further experience is needed to establish its safety and efficacy. The present review contains a summary of the risk management of therapeutic colonoscopy including ESD for large colorectal mucosal neoplasia, debated at the Endoscopic Forum Japan 2006, Hakone, and discussion of the problems and future prospects of these procedures.