Tips for difficult colorectal endoscopic submucosal dissection

Colorectal endoscopic submucosal dissection (ESD) is now widely performed and firmly established in the treatment of early-stage colorectal cancer. In particular, there have been many studies on difficult cases of colorectal ESD. Difficult cases can be divided into two groups: difficult dissection of the lesions and difficult approach to the lesion. In most cases, a combination of strategies can solve the problem. Challenging lesions such as those in the anal canal and ileum can also be treated from an anatomical perspective. In the rectum, there are no limits to size or circumference. In addition, the indications for ESD in patients without risk of metastasis other than deep invasion are being considered. Therefore, when ESD is performed on difficult lesions, it is necessary to ensure the quality of dissection