Underwater endoscopic mucosal resection: The third way for en bloc resection of colonic lesions?

BACKGROUND: Underwater endoscopic mucosal resection without submucosal injection has been described for removing large flat colorectal lesions.

OBJECTIVE: We aim to evaluate the reproducibility of this technique in terms of ease of implementation, safety and efficacy.

METHODS: A prospective observational study of consecutive underwater endoscopic mucosal resection in a community hospital was performed.

RESULTS: From September 2014 to April 2015, 25 flat or sessile colorectal lesions (median size 22.8 mm, range 10-50 mm; 18 placed in the right colon) were removed in 25 patients. Two of the lesions were adenomatous recurrences on scar of prior resection and one was a recurrence on a surgical anastomosis. The resection was performed en bloc in 76% of the cases. At the pathological examination, 14 lesions (56%) had advanced histology and seven (28%) were sessile serrated adenomas (two with high-grade dysplasia). Complete resection was observed in all the lesions removed en bloc. Intra-procedural bleeding was observed in two cases; both were managed endoscopically and were uneventful. No major adverse events occurred.

CONCLUSION: Underwater endoscopic mucosal resection appears to be an easy, safe and effective technique in a community setting. Further studies evaluating the efficacy of the technique (early and late recurrence), as well as comparing it with traditional mucosal resection, are warranted.