6. Colorectal Endoscopic Submucosal Dissection

Endoscopic submucosal dissection (ESD) has emerged as the approach with the greatest potentially curative yield with the major advantage being the ability to achieve en bloc excision for early stage neoplasms and allowing an accurate estimation of the risk of lymph node metastasis as well as of the clearance of resection margins. Nowadays, colorectal ESD has been implemented with standard indications and is widely diffused in East Asia and Japan where en bloc resection is the primary target. However, its application is still debated in Europe and the United States in favor of endoscopic mucosal resection (EMR) because of the greater technical difficulty, longer operating times, and increased risk of perforation. The progress in colorectal ESD indications is reported, and the approach of resection should be selected according to the estimation of the risk of SM invasion. Differences in training systems between Japan and the West are underlined. The use of animal models is strongly recommended before starting learning curve on humans, along with the need of accumulating the experience from the rectum to the colon on a step-by-step basis. Moreover, endoscopists should be aware of the possibility of using hybrid techniques during the learning of colorectal ESD to reduce the technical challenge of completing the procedure. ESD is safe and effective when performed by experienced endoscopists, and it is reasonable to assume that its use for colorectal neoplasms will spread widely in the future given the continuing development of strategies and technology refinements.