Effectiveness and safety of cold snare polypectomy and cold endoscopic mucosal resection for 10-19 mm non-pedunculated colorectal polyps: a multicenter observational cohort study.

Background and Aims: CSP is standard of care for resecting small (<10mm) colonic polyps. Limited data exist for its efficacy for medium-sized (10-19mm) non-pedunculated polyps, especially conventional adenomas. This study evaluated the effectiveness and safety of CSP/C-EMR for medium-sized non-pedunculated colonic polyps. Methods: A prospective multicentre observational study was conducted between May-2018 and June-2021 of all morphologically suitable 10-19mm non-pedunculated colonic polyps removed by CSP/C-EMR. Once resection was complete, multiple biopsies were taken of the margins circumferentially and centrally. Primary outcome: Incomplete resection rate (IRR) based on residual polyp in these biopsy specimens. Secondary outcomes: Recurrence rate at first surveillance colonoscopy and rates of adverse events. Results: CSP/C-EMR was performed for 350 polyps in 295 patients. Median polyp size: 15mm. 266 (76.0%) Paris 0-IIa classification. Submucosal injection used for 87.1%(n=305) of polyps. Histology:68.5% adenomas, 26.2% SSL without dysplasia, 3.8% SSL with dysplasia and 1.4% hyperplastic. Primary outcome: IRR based on margin or central biopsies being positive was 1.7%(n=6) and 0.3%(n=1) respectively. Secondary outcomes: Polyp recurrence rate was 1.7%(n=4) at first surveillance colonoscopy that was completed for 65.4%(n=229) of polyps at median interval of 9.7 months. Adverse events occurred in 3.4%(n=10) of patients: 1 intraprocedural bleed treated with clips, 3 self-limiting post-polypectomy bleeds, 4 post-polypectomy pain; 2 post-polypectomy-syndrome-like presentations. There were no perforations. Conclusion: CSP/C-EMR for morphologically suitable 10-19mm non-pedunculated colonic polyps is effective and safe, including for conventional adenomas. Rates of incomplete resection and recurrence were low, with few adverse events. Studies directly comparing to hot snare resection are required.

Publication History

Received: 09 June 2022

Accepted after revision: 07 February 2023

Accepted Manuscript online:
07 February 2023