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

Abstract

Background

Endoscopic mucosal resection (EMR) techniques for large (≥20 mm) nonpedunculated colorectal polyps (LNPCPs) have expanded with the introduction of ablation and cold EMR. This study assessed adverse events (AEs) for the newer EMR techniques, including cold EMR, compared with hot EMR.

Methods

We conducted a secondary analysis of four prospective multicenter studies of consecutive patients with LNPCPs undergoing EMR from 2019 to 2024. The primary outcome was serious AEs (SAEs) with cold and hot EMR. Secondary outcomes included SAEs in the hot EMR subgroups (no ablation [hEMR], margin ablation [hEMR-m], margin and base ablation [hEMR-mb]).

Results

1762 patients (mean age 65.8; 1890 LNPCPs) were included: 522 cold and 1368 hot EMRs (368 hEMR, 770 hEMR-m, 230 hEMR-mb). SAEs were higher with hot EMR (4.7%, 95%CI 3.6%–5.9%) vs. cold EMR (1.9%, 95%CI 0.9%–3.5%), also for the subgroups of hEMR (6.0%, 95%CI 3.8%–8.9%), hEMR-m (3.9%, 95%CI 2.6%–5.5%), and hEMR-mb (5.2%, 95%CI 2.7%–8.9%). Serious postendoscopic bleeding (PEB) was numerically higher with hot EMR (2.3%, 95%CI 1.6%–3.3%) vs. cold EMR (1.3%, 95%CI 0.5%–2.7%), also for the subgroups of hEMR (3.0%, 95%CI 1.5%–5.3%), hEMR-m (1.9%, 95%CI 1.1%–3.2%), and hEMR-mb (2.6%, 95%CI 1.0%–5.6%). Perforation, intraprocedural and post-procedural, was numerically higher with hot EMR (1.2%, 95%CI 0.7%–2.0%) vs. cold EMR (0.2%, 95%CI 0.0%–1.1%). hEMR-m and hEMR-mb with clipping had lower rates of serious and overall PEB than no clipping.

Conclusions

Cold EMR demonstrated lower rates of SAEs, serious PEB, and perforation compared with hot EMR. Perforation and mortality occurred almost exclusively after hot EMR. Hot EMR with margin +/− base ablation did not increase SAEs compared with hot EMR without ablation.

Publication History

Received: 12 February 2025

Accepted after revision: 24 July 2025

Accepted Manuscript online:
24 July 2025

Article published online:
23 September 2025

• References

• 1 Ferlitsch M, Hassan C, Bisschops R. et al. Colorectal polypectomy and endoscopic mucosal resection: European Society of Gastrointestinal Endoscopy (ESGE) Guideline – Update 2024. Endoscopy 2024; 56: 516-545
• 2 Djinbachian R, Rex DK, Chiu HM. et al. International consensus on the management of large (≥20 mm) colorectal laterally spreading tumors: World Endoscopy Organization Delphi study. Dig Endosc 2024; 36: 1253-1268
• 3 Bahin FF, Pellise M, Williams SJ. et al. Extended endoscopic mucosal resection does not reduce recurrence compared with standard endoscopic mucosal resection of large laterally spreading colorectal lesions. Gastrointest Endosc 2016; 84: 997-1006 e1
• 4 Pellise M, Burgess NG, Tutticci N. et al. Endoscopic mucosal resection for large serrated lesions in comparison with adenomas: a prospective multicentre study of 2000 lesions. Gut 2017; 66: 644-653
• 5 Moss A, Bourke MJ, Williams SJ. et al. Endoscopic mucosal resection outcomes and prediction of submucosal cancer from advanced colonic mucosal neoplasia. Gastroenterology 2011; 140: 1909-1918
• 6 Burgess NG, Metz AJ, Williams SJ. et al. Risk factors for intraprocedural and clinically significant delayed bleeding after wide-field endoscopic mucosal resection of large colonic lesions. Clin Gastroenterol Hepatol 2014; 12: 651-661.e1–e3
• 7 Heldwein W, Dollhopf M, Rösch T. et al. The Munich Polypectomy Study (MUPS): prospective analysis of complications and risk factors in 4000 colonic snare polypectomies. Endoscopy 2005; 37: 1116-1122
• 8 Rex DK, Lahr RE, Peterson MM. et al. Impact of including epinephrine in the submucosal injectate for colorectal EMR on postprocedural pain: a randomized controlled trial. Gastrointest Endosc 2022; 95: 535-539 e1
• 9 O'Sullivan T, Cronin O, van Hattem WA. et al. Cold versus hot snare endoscopic mucosal resection for large (≥15 mm) flat non-pedunculated colorectal polyps: a randomised controlled trial. Gut 2024; 73: 1823-1830
• 10 Steinbrück I, Ebigbo A, Kuellmer A. et al. Cold versus hot snare endoscopic resection of large nonpedunculated colorectal polyps: randomized controlled German CHRONICLE trial. Gastroenterology 2024; 167: 764-777
• 11 Meulen LWT, Bogie RMM, Winkens B. et al. Thermal ablation of mucosal defect margins to prevent local recurrence of large colorectal polyps: a systematic review and meta-analysis. Endosc Int Open 2022; 10: E1127-E1135
• 12 Klein A, Tate DJ, Jayasekeran V. et al. Thermal ablation of mucosal defect margins reduces adenoma recurrence after colonic endoscopic mucosal resection. Gastroenterology 2019; 156: 604-613 e3
• 13 Sidhu M, Shahidi N, Gupta S. et al. Outcomes of thermal ablation of the mucosal defect margin after endoscopic mucosal resection: a prospective, international, multicenter trial of 1000 large nonpedunculated colorectal polyps. Gastroenterology 2021; 161: 163-170 e3
• 14 Djinbachian R, Pohl H, Rex DK. et al. Thermal ablation after endoscopic mucosal resection of large colorectal polyps: not only the margins, but also the base?. Gut 2023; 73: 12-15
• 15 von Elm E, Altman DG, Egger M. et al. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for reporting observational studies. Lancet 2007; 370: 1453-1457
• 16 Holmes I, Kim HG, Yang DH. et al. Avulsion is superior to argon plasma coagulation for treatment of visible residual neoplasia during EMR of colorectal polyps (with videos). Gastrointest Endosc 2016; 84: 822-829
• 17 Burgess NG, Bassan MS, McLeod D. et al. Deep mural injury and perforation after colonic endoscopic mucosal resection: a new classification and analysis of risk factors. Gut 2017; 66: 1779-1789
• 18 Cha JM, Lim KS, Lee SH. et al. Clinical outcomes and risk factors of post-polypectomy coagulation syndrome: a multicenter, retrospective, case-control study. Endoscopy 2013; 45: 202-207
• 19 Nass KJ, Zwager LW, van der Vlugt M. et al. Novel classification for adverse events in GI endoscopy: the AGREE classification. Gastrointest Endosc 2022; 95: 1078-1085.e8
• 20 Pohl H, Rex DK, Barber J. et al. Comparable long-term efficacy of cold and hot EMR of large colon polyps: follow-up results of a randomized trial. Gastrointest Endosc 2025; 57: S85
• 21 Nogales O, Carbonell Blanco C, Montori Pina S. et al. Cold snare endoscopic mucosal resection versus standard hot technique for large flat nonpedunculated colonic lesions: a randomized controlled trial. Endoscopy 2025; 57: 851-861
• 22 Yi S, Cai Q, Zhang L. et al. Association between prophylactic closure of mucosal defect and delayed adverse events after endoscopic resection: a systematic review and meta-analysis. BMJ Open 2024; 14: e077822
• 23 Guardiola JJ, Rex DK, Thompson CC. et al. A new through-the-scope clip with anchor prongs is safe and successful for a variety of endoscopic uses. Endosc Int Open 2024; 12: E812-E817
• 24 Mohammed A, Gonzaga ER, Hasan MK. et al. Low delayed bleeding and high complete closure rate of mucosal defects with the novel through-the-scope dual-action tissue clip after endoscopic resection of large nonpedunculated colorectal lesions (with video). Gastrointest Endosc 2024; 99: 83-90 e1
• 25 Takayanagi D, Nemoto D, Isohata N. et al. Histological comparison of cold versus hot snare resections of the colorectal mucosa. Dis Colon Rectum 2018; 61: 964-670
• 26 Hirasawa K, Sato C, Makazu M. et al. Coagulation syndrome: Delayed perforation after colorectal endoscopic treatments. World J Gastrointest Endosc 2015; 7: 1055-1061
• 27 Sijmons JML, Grüter AAJ, Toorenvliet BR. et al. Short-term morbidity and mortality after right hemicolectomy: an update of national performance in the Netherlands. Colorectal Dis 2024; 26: 1983-1995
• 28 Gauci JL, Whitfield A, Medas R. et al. Prevalence of endoscopically curable low-risk cancer among large (≥20 mm) nonpedunculated polyps in the right colon. Clin Gastroenterol Hepatol 2025; 23: 555-563 e1
• 29 Peery AF, Cools KS, Strassle PD. et al. Increasing rates of surgery for patients with nonmalignant colorectal polyps in the United States. Gastroenterology 2018; 154: 1352-1360 e3
• 30 Hamada Y, Tanaka K, Ikenoyama Y. et al. Risk factors associated with painful colonoscopy and prolonged cecal intubation time in female patients. J Anus Rectum Colon 2023; 7: 168-175
• 31 Park DI, Kim HJ, Park JH. et al. Factors affecting abdominal pain during colonoscopy. Eur J Gastroenterol Hepatol 2007; 19: 695-659
• 32 Desomer L, Tate DJ, Pillay L. et al. Intravenous paracetamol for persistent pain after endoscopic mucosal resection discriminates patients at risk of adverse events and those who can be safely discharged. Endoscopy 2023; 55: 611-619
• 33 Bielawska B, Day AG, Lieberman DA. et al. Risk factors for early colonoscopic perforation include non-gastroenterologist endoscopists: a multivariable analysis. Clin Gastroenterol Hepatol 2014; 12: 85-92
• 34 Rutter MD, Nickerson C, Rees CJ. et al. Risk factors for adverse events related to polypectomy in the English Bowel Cancer Screening Programme. Endoscopy 2014; 46: 90-97
• 35 Hong JY, Kweon SS, Lee J. et al. Risk factors for procedure-related complications after endoscopic resection of colorectal laterally spreading tumors. Medicine (Baltimore) 2018; 97: e12589