Geometry of cold snare polypectomy and risk of incomplete resection

Abstract

Background Cold snare polypectomy (CSP) is safer than and equally efficacious as hot snare polypectomy (HSP) for the removal of small (<10mm) colorectal polyps. The maximum polyp size that can be effectively managed by piecemeal CSP (p-CSP) without an excessive burden of recurrence is unknown.

Methods Resection error risks (RERs), defined as the estimated likelihood of incomplete removal of adenomatous tissue for a single snare resection pass, for CSP and HSP were calculated, based on an incomplete resection rate. Polyp area, snare size, estimated number of resections, and optimal resection defect area were modeled. Overall risk of incomplete resection (RIR) was defined as RIR=1 – (1 – p)ⁿ, where p is the RER and n the number of resections.

Results A 40-mm polyp has a four times greater area than a 20-mm polyp (314.16mm² vs. 1256.64mm²), and requires three times more resections (11 vs. 33, respectively, assuming 8-mm piecemeal resection pieces for p-CSP). RIRs for a 40-mm polyp by HSP and p-CSP were 15.1%–23% and 40.74%–60.60% respectively.

Conclusion RER is more important with p-CSP than with HSP. The number of resections, n, and consequently RIR increases with increasing polyp size. Given the overwhelming safety of CSP, specific techniques to minimize the RER should be studied and developed.

Publication History

Received: 28 March 2023

Accepted after revision: 29 September 2023

Accepted Manuscript online:
29 September 2023

Article published online:
17 January 2024

• References

• 1 Siegel RL, Miller KD, Jemal A. Cancer Statistics, 2017. CA Cancer J Clin 2017; 67: 7-30
• 2 Hardcastle JD, Chamberlain JO, Robinson MH. et al. Randomised controlled trial of faecal-occult-blood screening for colorectal cancer. Lancet 1996; 348: 1472-1477
• 3 Chang LC, Shun CT, Hsu WF. et al. Risk of delayed bleeding before and after implementation of cold snare polypectomy in a screening colonoscopy setting. Endosc Int Open 2019; 7: E232-E238
• 4 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
• 5 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.e1–3
• 6 Sidhu M, Forbes N, Tate DJ. et al. A randomized controlled trial of cold snare polypectomy technique: technique matters more than snare wire diameter. Am J Gastroenterol 2022; 117: 100
• 7 Pohl H, Srivastava A, Bensen SP. et al. Incomplete polyp resection during colonoscopy-results of the complete adenoma resection (CARE) study. Gastroenterology 2013; 144: 74-80.e1
• 8 Kudo T, Horiuchi A, Kyodo R. et al. Mucosal defect size predicts the adequacy of resection of ≤10mm nonpedunculated colorectal polyps using a new cold snare polypectomy technique. Eur J Gastroenterol Hepatol 2021; 33 (Suppl. 01) e484-e489
• 9 Weisstein E. MathWorld - A Wolfram web resource. https://mathworld.wolfram.com/DiskCoveringProblem.html
• 10 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
• 11 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
• 12 van Hattem WA, Shahidi N, Vosko S. et al. Piecemeal cold snare polypectomy versus conventional endoscopic mucosal resection for large sessile serrated lesions: a retrospective comparison across two successive periods. Gut 2021; 70: 1691-1697
• 13 Belderbos TD, Pullens HJ, Leenders M. et al. Risk of post-colonoscopy colorectal cancer due to incomplete adenoma resection: A nationwide, population-based cohort study. United European Gastroenterol J 2017; 5: 440-447
• 14 Pohl H, Anderson JC, Aguilera-Fish A. et al. Recurrence of colorectal neoplastic polyps after incomplete resection. Ann Intern Med 2021; 174: 1377-1384
• 15 Tutticci NJ, Kheir AO, Hewett DG. The cold revolution: How far can it go?. Gastrointest Endosc Clin N Am 2019; 29: 721-736
• 16 Tate DJ, Desomer L, Klein A. et al. Adenoma recurrence after piecemeal colonic EMR is predictable: the Sydney EMR recurrence tool. Gastrointest Endosc 2017; 85: 647-656.e6
• 17 Moss A, Williams SJ, Hourigan LF. et al. Long-term adenoma recurrence following wide-field endoscopic mucosal resection (WF-EMR) for advanced colonic mucosal neoplasia is infrequent: results and risk factors in 1000 cases from the Australian Colonic EMR (ACE) study. Gut 2015; 64: 57-65
• 18 Shahidi N, Vosko S, Gupta S. et al. Previously attempted large nonpedunculated colorectal polyps are effectively managed by endoscopic mucosal resection. Am J Gastroenterol 2021; 116: 958-966
• 19 Abdallah M, Ahmed K, Abbas D. et al. Cold snare endoscopic mucosal resection for colon polyps: a systematic review and meta-analysis. Endoscopy 2023;
• 20 Suresh S, Zhang J, Ahmed A. et al. Risk factors associated with adenoma recurrence following cold snare endoscopic mucosal resection of polyps ≥ 20 mm: a retrospective chart review. Endosc Int Open 2021; 9: E867-E873
• 21 Mangira D, Cameron K, Simons K. et al. Cold snare piecemeal EMR of large sessile colonic polyps ≥20mm (with video). Gastrointest Endosc 2020; 91: 1343-13dfc\52
• 22 Piraka C, Saeed A, Waljee AK. et al. Cold snare polypectomy for non-pedunculated colon polyps greater than 1 cm. Endosc Int Open 2017; 5: E184-E189