Objective: Endoscopic resection of colorectal polyps is widely established as the optimal method to manage precancerous lesions. But the optimal technique for removal of the polyps is uncertain. The aim of this study was to compare the efficacy and safety of three methods for the management of 6-20mm colorectal polyps.Methods: A prospective, randomised controlled trial was conducted at the 900TH Hospital of Joint Logistics Support Force in Fujian, China. Endoscopically diagnosed colorectal polyps, 6-20 mm in size, were randomly assigned to the cold snare polypectomy (CSP), cold snare endoscopic mucosal resection (CS-EMR) or endoscopic mucosal resection (EMR) group. After polypectomy, additional 3-5 forceps biopsies by leading narrow-band imaging (NBI) were performed at the base and margins of polypectomy sites to assess the presence of residual polyp tissue and all samples were sent for histopathological analysis to assess completeness of resection. Polypectomy timing, tissue retrieval and complications were recorded at the time of the procedure.Results: A total of 781 polyps in 404 patients were assessed and randomly assigned to each group. Of these, 763 polyps were finally analyzed based on the pathology results. The complete resection rates with CSP, CS-EMR and EMR were 81.6%, 94.1% and 95.5%, respectively (p < .001). The intraprocedural bleeding rate, immediately after polypectomy, was significantly higher in the CSP group than in the CS-EMR and EMR group (9.4% vs. 4.4% vs. 1.9%; p < .001). However,delayed bleeding was higher in the EMR group than in the CSP and CS-EMR group (2.6% vs. 1.2% vs. 0.8%, respectively; p = .215). In the multivariate analysis showed that the operation method, lesion size, morphology and the number of resection were independent risk factors for complete resection rate (CRR) (p < .05), but the location and pathological classification of polyps had no significant influence on CRR.Conclusions: CS-EMR is safe and effective in the treatment of 6-20 mm colorectal polyps. Especially for 6-15 mm non-pedunculated polyps, CS-EMR has a high histological complete resection rate comparable to EMR, and retains the low risk of delayed complications after polypectomy with cold snare. CS-EMR is expected to become a more valuable new cold-cutting technique after cold snare polypectomy.
Keywords: Colorectal polyps; adverse events; cold snare endoscopic mucosal resection; cold snare polypectomy; complete resection rates; endoscopic mucosal resection.