Adverse events of cold snare compared to hot snare and ablation endoscopic mucosal resection for large colorectal polyps

Background and Study Aims Endoscopic mucosal resection (EMR) techniques for large (≥20 mm) non-pedunculated colorectal polyps (LNPCPs) have expanded with the introduction of ablation and cold EMR (cEMR). This study assessed adverse events for newer EMR techniques including cEMR compared to hot EMR. Patients and Methods We conducted a secondary analysis of four prospective multicenter studies of consecutive patients with LNPCPs undergoing EMR from 2019-2024. Primary outcome was serious adverse events (SAEs) with cEMR and hot EMR. Secondary outcomes included SAEs with hot EMR subgroups (no ablation [hEMR], margin ablation [hEMR-m], margin and base ablation [hEMR-mb]). Results 1762 patients (mean age 65.8y, 1890 LNPCPs) were included: 522 cEMRs and 1368 hot EMRs (368 hEMR, 770 hEMR-m, 230 hEMR-mb). SAEs were higher with hot EMR (4.7%, 3.6-5.9) compared to cEMR (1.9%, 0.9-3.5), including in subgroups of hEMR (6.0%, 3.8-8.9), hEMR-m (3.9%, 2.6-5.5) and hEMR-mb (5.2%, 2.7-8.9). Serious post-endoscopic bleeding (PEB) was numerically higher with hot EMR (2.3%, 1.6-3.3) compared to cEMR (1.3%, 0.5-2.7), including in subgroups of hEMR (3.0%, 1.5-5.3), hEMR-m (1.9%, 1.1-3.2) and hEMR-mb (2.6%, 1.0-5.6). Perforation, intraprocedural and postprocedural, was numerically higher with hot EMR (1.2%, 0.7-2.0) compared to cEMR (0.2%, 0.0-1.1). hEMR-m and hEMR-mb with clipping had lower serious and overall PEB than without clipping. Conclusions Cold EMR demonstrated lower rates of SAEs, serious PEB and perforation compared to hot EMR. Perforation and mortality occurred almost exclusively after hot EMR. Hot EMR with margin ± base ablation did not increase SAEs compared to hot EMR without ablation.

Publication History

Received: 12 February 2025

Accepted after revision: 24 July 2025

Accepted Manuscript online:
24 July 2025