Conventional Colonoscopy Including Indigo Carmine Dye Spray

With recent advances in endoscopic diagnostic and therapeutic technology, the preoperative endoscopic diagnosis of T1 (submucosal) carcinomas will become more important for determining whether detected T1 carcinoma can be cured by endoscopy alone (lesions with <1000 μm submucosal invasion) or should be treated by surgery (lesions with ≥1000 μm submucosal invasion). Useful conventional colonoscopic findings suggestive of polypoid-type T1b carcinomas are as follows: an expansion appearance, tumor stiffness or unevenness in the comprehensive view, coarse surface findings, converging folds toward the tumor, poor extension of the surrounding colonic wall, and stiffness or deformity of the colonic lumen. Similarly, useful conventional colonoscopic findings suggestive of flat and depressed-type T1b carcinomas are as follows: an expansion appearance, tumor stiffness or unevenness, protrusion in the depression surface, uneven depression surface, strong redness, converging folds toward the tumor, colonic wall deformity, stiffness of the colonic lumen, and table-like protrusion. If at least one of these colonoscopic findings is detected, then surgery should be considered. However, if none of these colonoscopic findings are detected, endoscopic resection (i.e., endoscopic polypectomy, endoscopic mucosal resection (EMR), and endoscopic submucosal dissection (ESD) depending on the lesion’s shape and size) can be performed.