Cold Snare Polypectomy Versus Cold Snare Polypectomy With Submucosal Injection for 3–9 mm Colorectal Polyps: A Randomized Controlled Trial

ABSTRACT Background and Aim Incomplete resection after cold snare polypectomy (CSP) remains a concern. CSP may sometimes require a forcible pull (“forced CSP”), which increases the incomplete resection rate (IRR). Submucosal injection before CSP (SI‐CSP) may facilitate resection and reduce IRR. We compared SI‐CSP with CSP for 3–9 mm polyps using an approach avoiding forced CSP. Methods This randomized controlled trial enrolled patients aged 40–79 years undergoing screening or surveillance colonoscopy with at least one 3–9 mm adenomatous or sessile serrated lesion. They were randomized in a 1:1 ratio into the SI‐CSP and CSP groups. If resection without forced CSP was not feasible, the procedure was converted to endoscopic mucosal resection (EMR). The primary outcome was the IRR, assessed by additional biopsies of the margins. Results Overall, 340 polyps from 340 patients were analyzed. Baseline characteristics were comparable between the groups. In the intention‐to‐treat analysis, the IRRs were low and similar between the SI‐CSP and CSP groups (0% vs. 1%, p = 1). SI‐CSP was associated with a lower EMR conversion rate (1% vs. 12%, p < 0.001), but median procedural time was longer (77 s vs. 54 s, p < 0.001). EMR conversion occurred exclusively for 6–9 mm polyps. Conclusions Avoiding forced CSP, with conversion to EMR when necessary, results in very low IRRs for SI‐CSP and CSP in 3–9 mm colorectal polyps. Compared with CSP, SI‐CSP does not reduce the IRR but reduces conversion to EMR. However, SI‐CSP requires a longer procedural time and additional resources for submucosal injection. Trial Registration Thai Clinical Trials Registry TCTR20240805001