229 Assessing Varying Techniques of Colonic Endoscopic Mucosal Resection and Subsequent Residual Adenoma at 6-Month Follow-Up

Abstract

INTRODUCTION: Local recurrence at colonic endoscopic mucosal resection (EMR) sites of medium to large polyps is common at first follow-up (∼10–30%). Extended edge resection has not shown a benefit of reducing this rate; however, edge ablation with snare tip soft coagulation has shown reduced local recurrence. Hybrid argon plasma coagulation (APC) is a novel technique, which can be used to treat microscopic residual disease to prevent local recurrence at follow-up surveillance colonoscopy. This study aims to evaluate if treating both the edges and base of an EMR site with a novel technique, hybrid APC, can reduce the rate of local recurrence at 6-month follow-up versus standard EMR assessing a single endoscopist. METHODS: This is a single center retrospective case series of all colonic EMRs with 6-month surveillance performed by a single endoscopist at a tertiary care center using both standard EMR and hybrid APC assisted EMR from May 2018 to May 2019. The main outcome measure was recurrence of precancerous polyp at prior EMR site at 6-month surveillance colonoscopy. Secondary outcome measures were the rate of procedure associated complications, including post-polypectomy bleeding and post-polypectomy syndrome. RESULTS: A total of 84 EMRs, 38 utilized hAPC, were performed from in the study period. 25 patients (mean age: 65.4 years, 48% men) with 30 polyps were included who completed surveillance colonoscopy after 6 months to evaluate for recurrence (Table 1). The average resected polyp size was 32 mm. Residual polyp recurrence occurred at 4 prior EMR sites (13.3%), with all of the recurrences occurring in patients who underwent standard EMR (100%). There was no recurrence of residual polyps in patients treated with hAPC assisted EMR. Further, 4 patients (15.4%) experienced post-polypectomy bleeding complications within 6 months, with all complications associated with patients treated with standard EMR (Table 2). There was a statistically non-significant trend toward higher recurrence and complication rate in patients treated with standard EMR compared to hAPC assisted EMR. CONCLUSION: In this retrospective study of colonic EMRs, the use of hAPC at initial EMR was associated with decreased local recurrence rate of precancerous tissue at EMR sites and rate of early complications. The findings of this early retrospective study warrant further studies to determine the efficacy of hAPC in reducing the recurrence rate after 6 months and how it compares to standard EMR procedure with snare tip soft coagulation.