Underwater colorectal EMR: Remodeling endoscopic mucosal resection

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Background Underwater EMR (UEMR) has been reported as a new technique for the removal of large sessile colorectal polyps without need for submucosal injection. Objective To evaluate (1) outcomes of UEMR, (2) whether UEMR can be easily performed by an endoscopist skilled in traditional EMR without specific dedicated training in UEMR, and (3) whether EUS is required before UEMR. Design Prospective, observational study. Setting Single, tertiary-care referral center. Intervention Underwater EMR. Main Outcome Measurements Complete resection and adverse events. Results A total of 72 consecutive patients underwent UEMR of 81 sessile colorectal polyps. EUS was performed before UEMR in 9 cases (11.1%) with a suspicious mucosal/vascular pattern. The mean polyp size was 18.7 mm (range 10-50 mm); the mean UEMR time was 11.8 minutes. Fifty-five polyps (68%) were removed en bloc, and 26 (32%) were removed with a piecemeal technique. Histopathology consisted of tubular adenomas (25.9%), tubulovillous adenomas (5%), adenomas with high-grade dysplasia (42%), serrated polyps (4.9%), carcinoma in situ (13.6%), and hyperplastic polyps (8.6%). Surveillance colonoscopy was scheduled at 3 months. Complete resection was successful in all patients. No adverse events or recurrence was recorded in any of the patients. Limitations Limited follow-up; single-center, uncontrolled study. Conclusion Interventional endoscopists skilled in conventional EMR performed UEMR without specific dedicated training. EUS may not be required for lesions with no invasive features on high-definition narrow-band imaging. UEMR appears to be an effective and safe alternative to traditional EMR and could eventually improve the way in which we can effectively and safely treat colorectal lesions.

Original languageEnglish
Pages (from-to)1238-1242
Number of pages5
JournalGastrointestinal Endoscopy
Issue number5
Publication statusPublished - May 1 2015

ASJC Scopus subject areas

  • Gastroenterology
  • Radiology Nuclear Medicine and imaging


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