Features of therapeutic devices for gastric endoscopic submucosal dissection and basic Techniques

Many endoscopic mucosal resection (EMR) techniques have been developed in Japan for the treatment of gastric mucosal lesions. They have become a popular practice not only in Japan but also in many Western countries. However, conventional EMR techniques have limitations in size and location. Piecemeal resection often becomes necessary in the case of large and difficult lesions. En bloc resection is desirable, because histological evaluations are essential to estimate the risk for lymph node metastasis, and prevention of local recurrence is also very important. To conduct reliable en bloc resection, endoscopic submucosal dissection (ESD) was developed using new electrosurgical knives specially designed for the ESD technique. The way of conducting an actual ESD procedure differs depending on the features of each knife. Operators should fully understand the features of these knives and select the appropriate one according to the situation and their skills. ESD is a wonderful technique that realizes en bloc resection of relatively large and difficult lesions that are impossible to treat by the conventional EMR technique.