Assessment of submucosal distortion and mass effect seen at follow-up after colorectal EMR with ORISE (with video)

ORISE (Boston Scientific, Marlborough, Mass, USA) is a viscous gel used for submucosal injection. We noted anecdotally that ORISE is associated with submucosal distortion of EMR scars at follow-up.We blindly reviewed photographs of 30 consecutive EMR scars at follow-up after resections using ORISE and 30 resections using other agents. Distortion was scored on a scale of 0 (no submucosal distortion) to 5 (overt submucosal distortion).The median submucosal distortion score at follow-up in ORISE cases was 3 (range, 0-5) versus 0 (range, 0-2) with other fluids (P .001, Mann-Whitney U test) by 1 reviewer and 3 (range, 0-5) versus 2 (range, 0-5), respectively, by a second reviewer (P = .018). The kappa value for agreement in the submucosal distortion scores between the 2 experts was .148 for all photographs and .214 for the ORISE cases (overall minimal agreement).ORISE can cause submucosal distortion in the region of EMR scars when they are viewed at follow-up. Such distortions must not be mistaken for submucosal tumor growth.