Colorectal endoscopic submucosal dissection using a gas-free saline-immersion dissection technique.

Recently, a new technique for performing underwater endoscopic submucosal dissection (ESD) in a saline solution has been reported [1] [2]. Although using a tapered hood is considered beneficial for underwater ESD in saline immersion, the bubbles generated during ESD can hinder smooth dissection [3]. We describe a gas-free saline-immersion technique for ESD, in which a tapered hood is filled with saline by pressing an air/water valve button, thus moving the bubbles to outside the hood.