Underwater EMR Outperforms Conventional EMR for 20- to 40-mm Nonpedunculated Polyps in Randomized Controlled Trial
Douglas K. Rex, MD, MASGE, reviewing Nagl S, et al. Gastroenterology 2021 Aug 6.
In a single-center randomized controlled trial from Germany, 148 nonpedunculated lesions 20 to 40 mm in size were included in a per-protocol analysis and randomized to underwater endoscopic mucosal resection (UEMR) or conventional EMR (CEMR). The primary outcome was the overall recurrence rate, which was 15.1% with UEMR and 24.6% with CEMR (P=.253). For lesions >30 mm to ≤40 mm, the recurrence rates were 6.3% with UEMR and 42.9% with CEMR (P=.031). En bloc resection rates and R0 resection rates were higher with UEMR than CEMR (33.3% vs 18.4% and 32.1% vs 15.8%, respectively). The en bloc resections occurred largely in the 20- to 30-mm size range. Five patients were converted from UEMR to CEMR because of intraprocedural hemorrhage. There were no perforations and no difference in delayed bleeding.
COMMENTThe differences in the primary endpoint could be easily eliminated by the inclusion of snare tip soft coagulation to the normal margin, which was not performed in this study but should be standard care now for CEMR and possibly also for UEMR. However, based on the available literature, it now seems clear to consider UEMR as a potential preferred method for achieving successful en bloc resections of lesions 10 to 30 mm in size when en bloc is most warranted, such as lesions with Paris 1s morphology or nongranular lesions with pseudodepression.
Note to readers: At the time we reviewed this paper, its publisher noted that it was not in final form and that subsequent changes might be made.
CITATION(S)
Nagl S, Ebigbo A, Goelder SK, et al. Underwater- versus conventional endoscopic mucosal resection of large sessile or flat colorectal polyps: a prospective randomized controlled trial. Gastroenterology 2021 Aug 6. (Epub ahead of print) (https://doi.org/10.1053/j.gastro.2021.07.044)
