[Efficacy of endoscopic treatment oncolorectal laterally spreading tumor and risk factors of delayed bleeding after operation].

Objective: To evaluate the endoscopic treatment efficacy of colorectal laterally spreading tumor (LST) and analyze the risk factors for delayed post-polypectomy bleeding (DPPB). Methods: Between January 2015 and December 2020, patients underwent colorectal endoscopic submucosal dissection (ESD) or hybrid ESD were recruited from the Second Affiliated Hospital of Zhejiang University. Complete resection rate, perforation rate, bleeding rate, operation time and lesion adhesion were compared between the ESD and hybrid ESD groups. Patients were divided into bleeding and non-bleeding groups based on the presence of DPPB. Multivariate logistic regression analysis was used to analyze the risk factors of DPPB. Results: A total of 665 patients with colorectal LST were enrolled, including 376 males and 289 females, with an average age of (57.4±0.4) years. There were 471 cases underwent ESD and 194 cases underwent hybridized ESD. There were no significant differences in gender, age, history of smoking and drinking, and prevalence of hypertension between the two groups (all P>0.05). Likewise, the rate of lesion adhesion (4.2% vs 7.7%, P=0.067), lesion complete resection (96.8% vs 93.8%, P=0.418), perforation (0.6% vs 1.0%, P=0.594), delayed bleeding (2.8% vs 2.1%, P=0.605) were not statistically significant between the two groups. Seventeen patients (2.6%) developed DPPB after endoscopic treatment. Multivariate logistic regression analysis showed that the lesion was in the rectum (OR=3.594, 95%CI: 1.237-10.443, P=0.019) and the diameter of the lesion>2 cm (OR=3.776, 95%CI: 1.411-10.106, P=0.008) were risk factors for DPPB. Conclusions: Both ESD and hybrid ESD are successful treatments for colorectal LST. Colorectal LST lesion site and lesion size>2 cm are risk factors of DPPB.