Safety and Efficacy of Cold Snare Polypectomy Without Submucosal Injection for Large Sessile Serrated Lesions: A Prospective Study

Cold snare polypectomy (CSP) has become the standard resection method for small colorectal polyps (<10 mm). Sessile serrated lesions (SSL) have low prevalence of advanced histology irrespective of size, and thus could be amenable to CSP. In this study, we evaluated the safety and efficacy of CSP for SSLs ≥10 mm.

Between November 2018 and January 2020, we prospectively enrolled 300 consecutive patients who underwent CSP for 474 SSLs ≥10 mm. To delineate SSL borders, indigo carmine chromoendoscopy and/or image-enhanced endoscopy was conducted. Piecemeal CSP (pCSP) was performed in cases where en-bloc resection was difficult. Biopsy specimens were obtained from the margins of the post-polypectomy defect to confirm complete resection. Surveillance colonoscopy was performed to screen for local recurrence.

All lesions were successfully resected using CSP without submucosal injection. The median diameter of the resected lesions was 14 mm, and pCSP was used to resect 106 (22%) lesions. Post-polypectomy biopsies revealed residual serrated tissue in only one case (0.2%). Adverse events included immediate bleeding in 8 (3%) patients; no delayed bleeding events occurred, irrespective of the use of antithrombotic drugs. During a 7-month median follow-up period, surveillance colonoscopies were performed for 384 lesions (81%), and no local recurrences were detected.

CSP without submucosal injection is a safe and effective treatment for SSLs ≥10 mm. UMIN Clinical Trials, Number: UMIN000034763.