Abstract:Abstract: Objective To investigate the situation and related risk factors of delayed postoperative hemorrhage after the endoscopic treations. Methods We retrospectively analyzed the clinical data, endoscopic surgical data and pathological data of the patients who had endoscopic mucosal dissection (ESD)/mucosal resection (EMR)/argon knife coagulation (APC) due to digestive tract lesions from June 2008 to June 2018, at the same time, among the patients who did not have delayed bleeding after endoscopic treatment under the same conditions, we selected samples randomly and formed a control group to analyze the clinical, endoscopic and pathological data of the patients in the control group. The following factors were statistically analyzed: related factors of patients: age, gender, anticoagulants; related factors of diseases: lesion size, lesion location, growth mode, tissue type; factors related to the operator’s proficiency and operation time. Results In this study, delayed hemorrhage mainly occurred in the dual-blood supply, and the site of abundant blood flow per unit time, mainly in males. Meanwhile, it was more common in the elderly in terms of age. Liver cirrhosis, diabetes, hypertension, hematological diseases and other related diseases, such as endogenous coagulation system, coagulation factor formation and platelet dysplasia, can increase the risk of delayed hemorrhage after endoscopic treatment. Compared with interstitial tumor, papilloma, inflammatory hyperplastic polyp, leiomyoma, and high-grade intrepithelial neoplasia, the risk of delayed hemorrhage of adenomatous disease is significantly increased, which is related to the abundance of blood supply in lesions. With the increase of operation time, we found that patients had an increased risk of delayed hemorrhage after surgery and were affected by the difficulty of surgery and operator proficiency. In terms of growth pattern, we found that the risk of delayed hemorrhage is the highest, which may be related to the need for submucosal injection of methylene blue and other related drugs to cause local mucosal swelling and increase the risk of surgical wound and blood vessel exposure under the same conditions. Conclusions Basic diseases, lesion location, lesion size, tissue type, operation time and operator proficiency are independent risk factors for delayed hemorrhage after endoscopic surgery.