Abstract
Endoscopic submucosal dissection (ESD) has been established as a standard endoscopic method for treatment of esophageal and gastric neoplasms, and as such has made rapid progress. However, colorectal ESD requires a high level of technical skill because of anatomical features of the colon. ESD becomes more difficult when fibrosis is present in the submucosal layer (sm fibrosis) . We compared the en bloc resection rate according to degree of fibrosis in the submucosal layer in 392 patients─totalling 401 lesions─who underwent colorectal ESD. The en bloc resection rate of severe fibrosis lesions was low (Table 1) . Between March 2011 and April 2012, colorectal ESD was performed in 110 cases at our hospital. Among the 23 cases (20.9%) with sm fibrosis, a severe degree of fibrosis was recognized in nine. Of these nine cases, the rate of en bloc resection was 55.6% (5/9) . The four cases in which en bloc resection was not possible were: two LST-G (Nodular mixed type) , one LST-NG (flat elevated type) and one Isp. Two of four lesions showed severe irregular type VI pit pattern and were deep SM invasive cancers. From a technical viewpoint, if the muscle layer could not be detected, en bloc resection without complications was very difficult. Hence colorectal ESD is not indicated in lesions which show severe irregular type VI pit pattern and severe sm fibrosis. It is necessary to clarify clinicopathological characteristics of lesions which present as severe sm fibrosis, and establish a therapeutic strategy for such cases.
