Pre-emptive Endoscopic Vacuum Therapy Reduces the Incidence of Anastomotic Leakage After Colorectal Cancer Surgery: a Randomized Controlled Study

Inclusion Criteria: 1. Pathologically diagnosed with colorectal cancer, planned for radical surgery (right hemicolectomy, left hemicolectomy, or anterior resection of the rectum, etc.). 2. Age 18-85 years, American Society of Anesthesiologists (ASA) classification I-III. 3. Anastomosis to be performed in a single stage (meeting anastomotic criteria). 4. Patient or legal guardian is able to understand and sign the informed consent form and comply with follow-up. Exclusion Criteria: 1. Preexisting anastomotic leakage or severe intra-abdominal infection before surgery. 2. Complicated by severe cardiovascular or cerebrovascular diseases (e.g., acute myocardial infarction, acute phase of cerebral infarction). 3. Severe liver or kidney dysfunction (liver function Child-Pugh class C, creatinine clearance \<30 ml/min). 4. Coagulation disorders (platelets \<50×10⁹/L, INR \>1.5) or receiving anticoagulant therapy that cannot be adjusted. 5. History of abdominal radiotherapy or multiple abdominal surgeries leading to severe intra-abdominal adhesions. 6. Complicated by other malignant tumors and currently undergoing radiotherapy or chemotherapy. 7. Psychiatric illness or cognitive impairment preventing compliance with the study.