Mo1716 SAFETY AND EFFICACY OF COLD SNARE VERSUS HOT SNARE ENDOSCOPIC MUCOSAL RESECTION (EMR) FOR NON-PEDUNCULATED POLYPS ≥ 20MM

Abstract

Background and Aims: Traditional endoscopic mucosal resection (EMR) using hot snare (HS-EMR) is associated with increased risks of bleeding and perforation for large polyps. Cold snare EMR (CS-EMR), which entails submucosal injection followed by cold snare polypectomy, is a newer technique that may be safer due to lack of electrocautery use and may be preferable in high-risk patients (i.e. elderly, patients on anticoagulants/antiplatelets). While data shows CS-EMR may be effective for polyps 10-20mm, there is little data on the use of CS-EMR for large polyps ! 20mm. This study aims to assess the safety and efficacy of CS-EMR versus HS-EMR for nonpedunculated polyps ! 20mm. Methods: We performed a retrospective study at a tertiary care referral center including patients undergoing piecemeal or en bloc CS-EMR or HS-EMR of non-pedunculated polyps ! 20mm from January 2015 to March 2019. Adverse events (AEs) were defined by presence of post-polypectomy syndrome, perforation, or delayed bleeding requiring hospitalization, blood transfusions or repeat colonoscopy, within 30 days of index colonoscopy. Efficacy was assessed by the absence of residual adenomatous tissue at follow-up colonoscopy completed from January 2015 to November 2019. Statistical comparison was performed using Fisher's exact test. Results: 209 patients (97 CS-EMR; 112 HS-EMR) with 220 colonic polyps ! 20mm (103 CS-EMR; 117 HS-EMR) were included. In the CS-EMR group, mean patient age was 66.7 years AE 11.3, 57.7% were male, and 36.1% were on anticoagulants/antiplatelets. In the HS-EMR group, mean patient age was 65.9 years AE 11.0, 56.3% were male, and 49.2% were on anticoagulants/antiplatelets. Mean polyp size was 29.3mm AE 10.2 in the CS-EMR group and 25.6mm AE 7.8 in the HS-EMR group. 140 (63.6%) colonic polyps had follow-up surveillance colonoscopies with a median of 271 (56-1316) days from index colonoscopy. Residual adenomas during follow-up (determined via biopsy at prior EMR site) were found in 14 (21.8%) CS-EMR cases and 23 (30.2%) HS-EMR cases, which were not significantly different (pZ0.337). Post-polypectomy bleeding (9.4% vs. 0%, p < 0.001) and composite adverse events of bleeding, perforation and post-polypectomy syndrome (12.0 % vs. 0%, p < 0.001) were higher in the HS-EMR group compared to the CS-EMR group. Conclusion: CS-EMR appears to be safe for resection of polyps ! 20mm with low rates of AEs and similar rates of adenoma clearance compared to HS-EMR. CS-EMR may be especially beneficial in high-risk patients. Significant rates of residual adenoma were present in both groups, which may be due to a tertiary referral center population with polyps previously manipulated, difficult locations including appendiceal orifice, and larger size of polyps. Additional randomized comparative studies are needed to demonstrate the safety and efficacy of CS-EMR compared to HS-EMR polypectomy.