Learning Curve of SILS in CRC

Inclusion Criteria: * 1\) Patients with indications for single-port laparoscopic surgery; 2) A single tumor was found during colonoscopy; 3) Preoperative biopsy confirmed by pathology as cancer or high-grade intraepithelial neoplasia; 4) The lesion is located in the lower segment of the sigmoid colon (20 cm to 25 cm from the proximal rectum), the junction of the sigmoid colon (16 cm to 20 cm from the proximal rectum), or the upper segment of the rectum (12 cm to 16 cm from the proximal rectum) \[31-33\]; 5) Intestinal anastomosis in vivo was performed through a tubular stapler. Exclusion Criteria: * 1\) Has undergone colorectal resection; 2) Preoperative CT assessment shows that the tumor stage is stage IV (as defined in the 8th edition of the American Joint Committee on Cancer (AJCC) "Cancer Staging Manual"); 3) Intestinal anastomosis was performed in vitro or not; 4) Received neoadjuvant therapy; 5) ASA classification is III-IV (in accordance with the ASA standards of the American Society of Anesthesiologists); 6) Life expectancy is less than one year; 7) There is a history of cancers other than thyroid cancer.