Evaluation of AL Prediction for Rectal Cancer

Inclusion Criteria: 1. Patients aged 18-75 years 2. Adenocarcinoma confirmed by pathology 3. Colonoscopy or imaging examination confirmed that the distance between the lower edge of the tumor and the anal edge was less than or equal to 12cm 4. Preoperative imaging diagnosis was cTxNxM0 5. No local complications (no obstruction, incomplete obstruction, no massive active bleeding, no perforation, abscess formation, and no invasion of adjacent organs) 6. The hematopoietic functions of heart, lung, liver, kidney and bone marrow meet the requirements of surgery and anesthesia 7. Voluntarily sign the informed consent form Exclusion Criteria: 1. Previous history of malignant tumor 2. Simultaneous multiple primary colorectal cancer 3. Previous multiple abdominal and pelvic surgeries or extensive abdominal adhesions 4. Patients with intestinal obstruction, intestinal perforation, intestinal bleeding, etc., requiring emergency surgery 5. Patients with familial adenomatous polyposis and active inflammatory bowel disease 6. A history of severe mental illness 7. pregnant or lactating women 8. Patients with uncontrolled infection before operation 9. The investigator did not consider the patient to be eligible for the trial