361 Endoscopic Submucosal Dissection for Colorectal (Cr-Esd) Malignant Polyps. Results of a Prospective Multicenter Western Cohort

Abstract

Introduction: Cold snare polypectomy (CSP) has been shown to be effective and safe for the removal of small adenomas (<10mm), resulting in less delayed post-polypectomy bleeding compared to snare polypectomy with cautery. Despite the development of specialized thin-wire snares, data comparing these devices for CSP with traditional thick-wire snares is scarce. Aim: We sought to assess the efficacy of a thin-wire snare compared to a thick-wire snare for CSP. Methods: A prospective, international, multi-centre randomized trial was performed (NCT02581254). The primary endpoint was the incomplete resection rate (IRR). All patients referred for colonoscopy were eligible. Exclusion criteria included lesions with evidence of submucosal invasion at colonoscopy. Upon detection of a suitable polyp (<10 mm and beyond the rectosigmoid), we performed a 1:1 randomization to use of a thin-wire (0.30 mm) or thick-wire (0.47 mm) snare for CSP. Only one polyp per patient was randomized. For patients with multiple polyps, the study polyp was the first polyp encountered. After complete endoscopic resection was achieved, two biopsies were performed from either side of the defect margin and sent to histopathology for analysis as separate specimens. All patients were contacted at 30 days to assess for adverse outcomes. Binary variables were assessed for significance using the chi-squared statistic (p<0.05). Results: Over 50 months to November 2019, 1195 patients were enrolled. 578 patients had no polyp detected. 617 patients (57.5% male) with polyps were then randomized to CSP with either thin-wire (nZ316) or thick-wire (nZ301) snare. Patient and procedural characteristics were similar between the groups (Table 1). Overall complete endoscopic resection was achieved in 99.8% (616/617). Marginal biopsies of the polypectomy defect were successfully performed in 609/617 cases (98.9%). Histopathology analysis showed; 61.8%-adenomas, 9%-serrated. The IRR for thin-and thick-wire snares was comparable at 1.4% versus 2.7% [RR-0.48, 95% CI (0.15-1.58), p Z 0.23]. Only one case of clinically significant post endoscopic bleeding was observed in the thin-wire snare arm. No other adverse events occurred in the cohort (Table 2). Conclusion: In this study, thin-and thick-wire snares were comparably efficacious when used for CSP of small polyps with minimal adverse events. Incomplete resection rates were lower than previously reported for both study arms. Therefore, optimal operator technique, maybe more important than snare design alone in CSP.