Abstract:To explore the clinical characteristics and risk factors of perforation during endoscopic submucosal dissection (ESD) of superficial colorectal tumor in elderly patients, clinical data including patients'' medical history, characteristics of colorectal lesions, operation process and prognosis in the elderly patients who underwent colorectal ESD at Beijing Friendship Hospital, Capital Medical University from January 2017 to October 2020 were retrospectively analyzed. A total of 278 patients were collected with the age of 68.62±6.82 years. There were 218 patients aged 60-< 75 years and 60 patients aged 75-< 90 years. There were 32 lesions at the ileocecum, 51 at the ascending colon, 20 at the transverse colon, 12 at the descending colon, 54 at the sigmoid colon, and 109 at the rectum. The long diameter of the lesions was 2.32±1.36 cm with 117 cases <2 cm, 138 cases 2-<5 cm, and 23 cases ≥5 cm. There were 150 adenomas, 23 high grade intraepithelial neoplasms, 65 malignant lesions, 18 neuroendocrine tumors, 3 benign lesions, and 19 inflammatory lesions. Intraoperative perforation occurred in 25 cases and postoperative perforation occurred in 2. The results showed that the incidence of perforation in the right half of the colon was higher than that in the left half. The incidence of perforation was higher in malignant lesions and those with larger long diameter of the lesion. Malignant lesions, long diameter ≥2 cm, and the lesion site are independent risk factors for ESD perforation.