Endoscopic submucosal dissection of early cancers and large flat adenomas.

For a reliable en bloc resection of large superficial lesions, we have been performing endoscopic submucosal dissection (ESD) using sodium hyaluronate and other assisting devices. The ESD using sodium hyaluronate uses the long-lasting mucosal protrusion for safety and ease of mucosal and submucosal incision with a needle knife. This enables en bloc resections of large superficial tumors without resorting to a snaring method. A transparent hood attached to the endoscope tip is used to safely assist precise control of a needle-knife tip while incising the mucosa. A small-caliber tip transparent hood (ST hood) is used to open the incised mucosa for better visualization of the submucosal tissue. Combined with the long-lasting submucosal thickening by locally injected sodium hyaluronate, an ST hood enables safe dissection of the submucosal layer with a needle knife. Effective control of bleeding during the procedure is also a key element for success. Argon plasma coagulation and/or a hemostatic forceps can be used to control bleeding during the procedure. Perforation is a major concern as a possible complication of ESD. It can be prevented by sufficiently thickening the submucosa by proper injection of sodium hyaluronate and careful selection of the incising layer. By using ESD with sodium hyaluronate and an ST hood, it is feasible to treat endoscopically large superficial tumors in the stomach, esophagus, and colon, which used to require surgical treatments.