Safety and Efficacy Study of Single-port Robotic Versus Multi-port Robotic Radical Rectal Cancer Surgery

Inclusion Criteria: * 18 years \< age ≤80 years * Tumor located in the mid to high rectum (lower edge of tumor ≥ 5 cm from anal verge) * Pathological rectal carcinoma * Clinically diagnosed c/ycT1-3N0-1M0 lesions according to the 8th Edition of AJCC Cancer Staging Manual * Tumor size of 10 cm or less * No history of other malignant tumors * ECOG score is 0-1 * ASA score is Ⅰ-Ⅲ * Informed consent Exclusion Criteria: * Body mass index (BMI) \>35 kg/m2 * Familial adenomatous polyposis (FAP) * Inflammatory bowel disease (IBD) * Multiple malignant colorectal tumors * Pregnant woman or lactating woman * Severe mental disease * Previous gastrointestinal surgery (except appendectomy ） * Combination of intestinal obstruction, bleeding, perforation requiring emergency surgery * Requirement of simultaneous surgery for other disease * Serious disorders of liver and kidney function, coagulation function, or severe underlying diseases that cannot tolerate the surgery. * Patients or family members who cannot understand the study program.