Re-evaluation of indications and outcomes of endoscopic excision procedures for colorectal tumors: a review.

Endoscopic submucosal dissection (ESD) and endoscopic mucosal resection (EMR) are useful therapeutic techniques for colorectal tumors. Currently, new techniques based on these procedures are available, such as endoscopic submucosal dissection with snare (ESD-S) and endoscopic mucosal resection with pre-cutting (EMR-P). For the excision of colorectal tumors, each of these techniques has been characterized as having a high total resection rate, low recurrence rate or low complication rate. In this study, we analysed clinical trials that had recently been published, to search for the most appropriate endoscopic treatment for colorectal tumors. Our search results revealed the following: for a tumor with a diameter less than 20 mm, the surgeon should choose ESD, ESD-S, EMR-P or EMR, depending on the condition of the tumor. On the other hand, to excise a tumor larger than 20 mm in diameter, ESD and ESD-S should be the first choices. However, if the patient has a high risk of complications due to ESD or ESD-S, the use of EMR-P would be suitable. Because of the high possibility of canceration in a tumor larger than 20 mm in diameter, EMR is not the optimal endoscopic treatment for the excision of a colorectal tumor, due to a low total resection rate and a high recurrence rate.