Cold Versus Hot Snare Polypectomy for Small Colorectal Polyps A Pragmatic Randomized Controlled Trial

Background: Although cold snare polypectomy (CSP) is considered effective in reducing delayed postpolypectomy bleeding risk, direct evidence supporting its safety in the general population remains lacking.Objective: To clarify whether CSP would reduce delayed bleeding risk after polypectomy compared with hot snare polypectomy (HSP) in the general population.Design: Multicenter randomized controlled study. (ClinicalTrials. gov: NCT03373136)Setting: 6 sites in Taiwan, July 2018 through July 2020.Participants: Participants aged 40 years or older with polyps of 4 to 10 mm.Intervention: CSP or HSP to remove polyps of 4 to 10 mm. Measurements: The primary outcome was the delayed bleeding rate within 14 days after polypectomy. Severe bleeding was defined as a decrease in hemoglobin concentration of 20 g/L or more, requiring transfusion or hemostasis. Secondary outcomes included mean polypectomy time, successful tissue retrieval, en bloc resection, complete histologic resection, and emergency service visits.Results: A total of 4270 participants were randomly assigned (2137 to CSP and 2133 to HSP). Eight patients (0.4%) in the CSP group and 31 (1.5%) in the HSP group had delayed bleeding (risk difference,-1.1% [95% CI,-1.7% to-0.5%]). Severe delayed bleeding was also lower in the CSP group (1 [0.05%] vs. 8 [0.4%] events; risk difference,-0.3% [CI,-0.6% to-0.05%]). Mean polypectomy time (119.0 vs. 162.9 seconds; difference in mean,-44.0 seconds [CI,-53.1 to-34.9 seconds]) was shorter in the CSP group, although successful tissue retrieval, en bloc resection, and complete histologic resection did not differ. The CSP group had fewer emergency service visits than the HSP group (4 [0.2%] vs. 13 [0.6%] visits; risk difference,-0.4% [CI,-0.8% to-0.04%]).Limitation: An open-label, single-blind trial.Conclusion: Compared with HSP, CSP for small colorectal polyps significantly reduces the risk for delayed postpolypectomy bleeding, including severe events.