Local recurrence and its risk factors after cold snare polypectomy of colorectal polyps

Background Local recurrence after cold snare polypectomy (CSP) of colorectal polyps has not been well analyzed. In this study, we analyzed the characteristics of local recurrence. Methods We retrospectively reviewed consecutive lesions resected by CSP from 2014 to 2016 and lesions that were followed up at >= 10 months after CSP, were analyzed. Our indication for CSP was a benign tumor of < 15 mm in size. We analyzed local recurrence and its risk factors using multivariate analyses. In addition, we compared lesions of >= 10 mm and < 10 mm. Moreover, therapeutic methods for recurrence were analyzed. Results Finally, we analyzed 554 cases out of 820 consecutive cases. The mean polyp size was 5.3 +/- 2.8 mm and theen blocresection and histopathological complete resection rates were 99.3% and 70.2%, respectively. The overall recurrence rate was 1.9% (mean follow-up period: 13.0 +/- 4.0 months). Significant differences were observed between 11 recurrent lesions and 543 lesions without recurrence regarding polyp size (8.0 +/- 3.7 mm vs. 5.2 +/- 2.7 mm,p < 0.001), rate of sessile-serrated polyp (27.3% vs. 3.0%,p < 0.001), and histopathological positive margin (45.4% vs. 3.7%,p = 0.019). Multivariate analyses showed that a histopathological positive margin was the only significant risk factor for local recurrence (OR 16.600, 95% CI 3.707-74.331,p < 0.001). Regarding the comparison between 74 lesions of >= 10 mm and 480 lesions of < 10 mm, significant differences were observed in theen blocresection rate (93.2% vs. 100%,p < 0.001), high-grade dysplasia rate (8.1% vs. 0.8%,p < 0.001), and histopathological complete resection rate (54.0% vs. 72.7%,p = 0.001). The recurrence rates of these two groups were 5.4% and 1.4%, respectively (p = 0.069). All recurrent cases could be resected with repeat CSP. Conclusions The local recurrence rate after CSP for lesions of < 10 mm was 1.4%. CSP was not recommended for lesions of >= 10 mm due to high rates of recurrence and malignancy.