Figure 3.

Endoscopic submucosal dissection (ESD) and double-scope methods. (A) Use of the ESD method in tumors that are surrounded by only muscle and serosa allows for a 10-mm incision to be opened that was as deep as the submucosal layer. (B) A perforation hole giving passage to a 5-mm diameter transnasal endoscope was opened in the incision; the endoscope was inserted into the abdominal cavity from the perforation hole and inverted intraperitoneally. A full-thickness resection of the gastric wall was subsequently performed safely, while a transnasal endoscope was used for observation.