ABSTRACT
Endoscopic submucosal dissection (ESD) has enabled en-bloc resection of superficial gastrointestinal tumors regardless of the size or location of the tumor. However ESD still poses a number of challenges for the experienced endoscopist. These challenges include the adaptation of a demanding technique, the higher incidence of complications, and a longer procedure time compared to standard endoscopic procedures. In this article, we describe the performance of ESD using the Flush Knife technique. We emphasize that the most important factor in the performance of ESD using the Flush Knife technique is maintaining the appropriate depth of dissection. Appropriate dissection of the branched vascular network at the mid-submucosal layer is required to reach the avascular stratum just above the muscle layer. This should be accomplished using the horizontal approach, such that the dissection plane remains as horizontal as possible with respect to the muscle layer. This approach will enable the interventional endoscopist to treat difficult cases with large vessels and severe fibrosis. And at the same time will secure high-quality resected specimens with excellent basal margins so that depth of invasion can be assessed very accurately.