A Randomized, Controlled, Multicenter, Noninferiority Clinical Study of Perioperative and Oncological Safety in Patients With Rectal Cancer

Inclusion Criteria:

1. Patients were aged between 18 and 75 years;
2. Pathologically confirmed as adenocarcinoma;
3. Colonoscopy or imaging examination confirmed that the distance between the lower edge of the tumor and the anal margin was ≤ 5cm;
4. Preoperative imaging diagnosis was ct1-3nxm0;
5. Preoperative colonoscopy or imaging diagnosis confirmed that the maximum diameter of the tumor was not more than 5cm;
6. Body mass index (BMI) ≤ 30kg / m2;
7. No local complications (no obstruction, incomplete obstruction, no massive active bleeding, no puncture Formation of pores and abscesses without invasion of adjacent organs);
8. The hematopoietic functions of heart, lung, liver, kidney and bone marrow meet the requirements of surgery and anesthesia;
9. Voluntary informed consent.

Exclusion Criteria:

1. Preoperative evaluation of patients with lateral lymph node metastasis;
2. Previous history of malignant tumor;
3. Simultaneous multiple primary colorectal cancer was diagnosed;
4. There are contraindications to laparoscopic surgery, such as severe cardiopulmonary insufficiency;
5. Patients who had undergone abdominal and pelvic surgery for many times or had extensive abdominal adhesions;
6. Patients with intestinal obstruction, intestinal perforation, intestinal hemorrhage and other emergency operations;
7. Patients with familial adenomatous polyposis, Lynch syndrome associated rectal cancer, and inflammatory bowel disease in the active phase;
8. Have a history of serious mental illness;
9. Pregnant or lactating women;
10. Patients with uncontrolled infection before operation;
11. The investigator considered that the patient should not participate in the trial.