863 UNDERWATER EMR (UEMR) OF LATERALLY SPREADING TUMORS INVOLVING THE ILEOCECAL VALVE

Abstract

Laterally spreading tumors (LSTs) involving the ileocecal valve (ICV) are often referred to surgery due to a higher risk of perforation or incomplete resection using conventional endoscopic mucosal resection (EMR) technique. We hypothesized that the "floating" effect of water on the IC valve, which has a high fat content, may facilitate EMR. Evaluate the feasibility, safety, and efficacy of UEMR without submucosal injection for the treatment of LSTs involving the ICV. Prospective, observational study using a standardized UEMR technique without prior submucosal injection. Patients scheduled for surveillance colonoscopy with biopsies at 6 months. Primary endpoints: Complete resection at index procedure and residual or recurrence at follow up. Secondary endpoint: Complications, including: immediate (up to 24h) bleeding, delayed (>24h) bleeding, perforation, and abdominal pain. Over 77 months, 102 consecutive patients (54% female, mean age 67) underwent attempted resection of LSTs at the ICV by UEMR. All had undergone prior colonoscopy elsewhere and 15 (15%) had been referred for surgical treatment. A previous unsuccessful attempt at resection had been performed in 20 patients (20%). Mean LST size was 29 mm (5 LSTs < 15 mm). UEMR was successful in 100 patients (98%), of whom 23 (23%) had en bloc resections. Mean total procedure time was 46 min and mean resection time was 14 min. Two patients had unsuccessful resections and were referred to surgery. Delayed bleeding occurred in 8 patients (8%), 7 of whom went to the ER, and 3 of whom were hospitalized (2 transfused, one sent for hemicolectomy). No perforations occurred, and no abdominal pain was reported. Final pathology: tubular adenoma (47), villous or tubulovillous adenoma (41), serrated adenomas (8), invasive adenocarcinoma (3), hyperplastic polyp (1), inflammatory polyp (1), and non-diagnostic tissue (1). Of 72 patients (71%) who completed surveillance residual adenoma was found in 2 (3%) patients on their first follow up colonoscopy and retreated by UEMR; one has been free of recurrence on third follow-up colonoscopy and one was lost to follow-up. In this large patient cohort, UEMR was found to enable successful and safe resection of LSTs involving the ICV with nearly no residual or recurrence observed in patients who completed surveillance. Water submersion may also protect against perforation. Further study is warranted.