A121 UNDERWATER EMR FOR NON-LIFTING SESSILE COLORECTAL LESIONS

Abstract

Abstract Background Sessile colorectal lesions which do not elevate with submucosal injection — “non-lifting” lesions — are considered poor candidates for EMR due to concerns of possible invasive cancer and increased procedural risk. However, a non-lifting sign is an unreliable predictor of malignancy, relegating many benign lesions to surgical resection. Underwater EMR (UEMR), which obviates submucosal injection, is effective for sessile colorectal polyps but has not been evaluated specifically for non-lifting lesions. Aims The aim of this study was to assess the efficacy of UEMR for “non-lifting” large sessile colorectal lesions with the hypothesis that UEMR may have a clinical role in managing complex lesions. Methods We reviewed our database from 2016 to 2019 for patients referred for large (≥ 20 mm) non-lifting colorectal lesions without overt signs of invasive cancer, who subsequently underwent UEMR. Results Thirty-two cases were successfully treated with single session UEMR. 18 (56%) were de novo lesions whereas the remainder had undergone previous attempt(s) at conventional EMR. The mean lesion size was 37 ± 17 mm. 4 cases (13%) were resected en bloc; the remainder piecemeal. Final pathology was T1 adenocarcinoma, N=3 (9%); tubulovillous adenoma, N=15 (47%); tubular adenoma, N=8 (25%); sessile serrated, N=6 (19%); high-grade dysplasia, N=2 (6%). One patient with cancer underwent surgical resection (T1N0); the remainder had endoscopic follow-up over 8 ± 3 months with benign recurrent/residual lesions in 8%, all amenable to UEMR. There were no procedural complications. Conclusions In this series of large sessile non-lifting colorectal lesions, UEMR was effective for both de novo and previously treated lesions, obviating surgery in the majority of cases. Funding Agencies None