Gas-Alternating-Water Infusion Method: A Novel Technique Of Endoscopic Submucosal Dissection For Colorectal Tumors Regardless Of Gravity

Gas-alternating-water infusion method with/without internal traction assistance: a novel technique of endoscopic submucosal dissection for large colorectal tumors regardless of gravity direction.

“…During conventional UESD [ 2 , 3 ], the body positions of patients must be changed depending on the direction of gravity with regard to the lesion, such as the left lateral decubitus position, right lateral decubitus position, supine position, and prone position. Unlike conventional UESD [ 2 , 3 ], our GAW-ESD [ 4 ] allows all the patients to be kept in the left lateral position during the whole procedure, regardless of the direction of gravity of the lesion. For the part of the lesion on the lower side of gravity, submucosal dissection may be performed assisted by buoyancy below the liquid surface; and for the other part on the upper side of gravity, submucosal dissection will be performed assisted by gravity above the liquid surface.…”

“…The current UESD method involves aspirating all the CO 2 gas and changing the patient’s posture to place the lesion at the lower side of gravity to allow for saline solution accumulation around the lesion, which seems troublesome under the condition of endotracheal intubation. To avoid the trouble of repeatedly altering the patient’s body positions according to the gravity direction of the lesion during UESD [ 2 , 3 ], a novel technique of colorectal ESD using the gas-alternating-water infusion method [ 4 ] (GAW-ESD), with or without internal traction assistance, depending on the level of exposure of the submucosal space, has been improved and introduced in our endoscopic center for treating large heavy colorectal tumors (≥ 3 cm in size).…”