Abstract: | Endoscopic submucosal dissection is becoming popular for large superficial gastric cancer in Japan. However, it is considered difficult in the colon because the colonic wall is much thinner than the gastric wall. We use several devices to overcome this difficulty and have made it feasible in the colon as well. Submucosal injection of sodium hyaluronate is used to maintain sufficient thickening of the submucosal tissue and a small‐caliber‐tip or regular cylindrical transparent hood is used to open up the incised mucosa as a substitute for countertraction. In this method, not only the lateral margin, but the vertical margin of the resection can also be determined precisely because submucosal incision is carried out under direct visualization of the submucosal tissue. |