An effective and safe gastric endoscopic submucosal dissection in the right lateral position using an inverted overtube

Figure 4 New right lateral position endoscopic submucosal dissection using gravity (A) and location and approach direction of electric knife the during right lateral endoscopic submucosal dissection (B). A: The rotation of the patients to the right lateral position (curved arrow) allows the inverted overtube to be placed through the mouth; B: As the direction of gravity to the stomach changes, the angle between the electric knife and the gastric mucosa is decreased to approximately 20 degrees, and the mucosa is located closer to the endoscope.