Title: Acetic acid-assisted underwater endoscopic mucosal resection for successful resection of sessile serrated lesions
Abstract: Underwater endoscopic mucosal resection (UEMR) has become the new standard of endoscopic resection of ≥ 10-mm non-pedunculated colonic polyps [1] [2] [3] [4]. It is particularly difficult to delineate the margins of sessile serrated lesions (SSLs). Though submucosal injection of a blue-colored dye mixture (e. g., indigo carmine or methylene blue) is used to enhance these lesions, SSLs tend to expand owing to the injection of the dye. Hence, bigger snares are utilized or more pieces of resection are needed, resulting in bigger defects after removal or non-en bloc resection.