Comparison of underwater and conventional endoscopic mucosal resection for removing sessile colorectal polyps: a propensity-score matched cohort study

Background and study aims Endoscopic mucosal resection (EMR) is a standard method for removing sessile colorectal polyps ≥ 10 mm. Recently, underwater EMR (UEMR) has been introduced as a potential alternative. However, the effectiveness and safety of UEMR compared with conventional EMR is un clear. Patients and methods In this 1:1 propensity score (PS) matched retrospective cohort study, we compared the en bloc resection rates, procedure time, intraprocedural and delayed bleeding rates, and incidence of muscle layer injury. We also performed subgroup analyses by sizes of polyps (