The efficacy and safety of cold snare polypectomy in intermediate nonpedunculated polyps.

BACKGROUND: Cold snare polypectomy (CSP) is increasingly popular because of its safety and convenience, but it is currently recognized as the best way to remove diminutive polyps (≤ 5 mm). CSP for nonpedunculated polyps ≥ 10 mm in size has not been well examined. We evaluate the safety and efficacy of CSP for benign-looking intermediate nonpedunculated polyps. METHODS: We reviewed intermediate nonpedunculated polyps that resected by CSP from 2021 to 2023. The lesions were carefully observed with high-definition white-light (HD-WL) endoscopy and magnifying endoscopy with narrow-band imaging (ME-NBI) before CSP. We analyzed lesion characteristics, complete resection, cold snare defect protrusion (CSDP), histopathology, adverse events, and recurrence/residual. We compared the differences between lesions 10-14 mm in size and lesions ≥ 15 mm in size. We also analyzed risk factors for recurrence/residual and incomplete resection. RESULTS: We retrospectively analyzed 631 lesions in 482 patients. The average size was 11.1 ± 1.3 mm, of which 3.3% were ≥ 15 mm. The CSDP rate was 34.1%. The rates of post-polypectomy bleeding (PPB), delayed post-polypectomy bleeding (DPPB), post-polypectomy perforation (PPP) and delayed post-polypectomy perforation (DPPP) were 0.3%, 0.2%, 0.0% and 0.0%, respectively. Two lesions were carcinoma in situ (0.3%) and seven lesions were high-grade dysplasia (HGD) (1.1%). The histological complete resection rate (the horizontal margin) was 94.3%. There were significant differences in sex, histological complete resection rate, and CSDP rate between lesions 10-14 mm in size and lesions ≥ 15 mm in size. CSDP was the only risk factor for incomplete resection of the polyps. CONCLUSION: CSP of intermediate nonpedunculated polyps is safe and effective. The recurrence/residual rate and the adverse event rate were low.