Abstract
Endoscopic submusosal dissection (ESD) was developed, and the reliable en-bloc resection of the lesions which were conventionally hard to be removed has come to be enabled. However, colorectal ESD is rather difficult skill and the risk of complication is high. Therefore, the deliberate attitude is expected in its introduction. The indications are the lesions which have difficulty to be treated by EMR but need the en-bloc resection, and the cases that functional disorder becomes the problem by the surgical operation. Clinicopathologically, the most appropriate indications are regarded as the laterally spreading tumors non-granular type that are larger than 20mm. But these are the representative difficult cases because of the severe fibrosis in the submucosal layer. At the point of safety, difficulty, and functional preservation, the rectal lesions show most remarkably the merits of colorectal ESD.
