Cold or Hot Snare with Endoscopic Mucosal Resection for 6-9 mm Colorectal Polyps: A Propensity Score Matching Analysis.

To investigate the efficacy and safety of cold snare endoscopic mucosal resection (CS-EMR) and hot snare endoscopic mucosal resection (HS-EMR) for colorectal polyps with diameters of 6-9 mm. Retrospective analysis was performed on the clinical data of 485 patients with colorectal polyps (6-9 mm in size) who were treated with CS-EMR or HS-EMR in the endoscopy center of Hangzhou Third People's Hospital from January 2017 to December 2019. Colorectal polyps were lifted by submucosal injection of normal saline. The CS-EMR group used a cold snare to remove the lifting polyps, while the HS-EMR group used a hot snare. Propensity score matching analysis with 1:1 matching and the nearest neighbor matching method were performed to ensure well-balanced characteristics of the CS-EMR and HS-EMR groups. Matching factors included age, gender, body mass index, blood routine, coagulation indicators, polyp site, size, number, and morphology. This resulted in a balanced cohort of 128 patients per group. Polyp recovery, complications, clipping for disclosure, and length of hospital stay were compared after matching. -Tests, χ tests, McNemar's tests, and Fisher's exact test were used for comparison between the two groups before and after matching. There were no differences between the two groups of intraoperative and postoperative bleeding ( > .05), but the CS-EMR clipping rate was lower than the HS-EMR group ( < .01). There was a higher incidence of post-polypectomy syndrome (PPS) ( = .03) and longer hospital stays ( < .01) in the HS-EMR group than the CS-EMR group. Compared with HS-EMR, CS-EMR is more convenient to operate, with a low incidence of PPS, clipping rates, and short hospital stays. It is a safe and effective removal method for 6-9 mm colorectal polyps.