Underwater endoscopic mucosal resection: an alternative treatment for large colorectal polyp removal

BACKGROUND: Large sessile/flat colonic polyps are traditionally removed by lift polypectomy. Underwater endoscopic mucosal resection (UEMR) is a novel technique where air is suctioned out and replaced by water to decompress the colon so that the flat lesions assumes a more polypoid shape facilitating its removal with the standard snare resection. We report the feasibility and safety in our series of patients utilizing this technique. METHODS: A retrospective, observational study of all patients who underwent removal of large colonic polyps (> 10 mm) over a period of 3 years (January 2012 to January 2015) at a tertiary care center by UEMR were included in the study. RESULTS : A total of 102 polyps were removed in 93 adult patients using UEMR. The mean age of patients was 64.7 +/- 9.7 years. The average number of polyps per patient was 1.84 +/- 1.3 with a range of 1-7. The range of the polyp size was 10 to 60 mm. The mean size of the polyp was 20.4 +/- 9.4 mm, median size 26.9 +/- 9.4 mm. Ninety-two (90.2%) were removed in piecemeal fashion and ten (9.8%) were removed en bloc. Delayed bleeding occurred in seven (9.7%) patients. CONCLUSIONS : In this largest series on UEMR, we report the feasibility and safety of this procedure. Future randomized trials comparing this technique versus standard lift polypectomy technique will further elucidate the benefit of one over other.