Clinical Research Directory

Inclusion Criteria: 1. Patients diagnosed with colorectal cancer or large adenoma who are suitable for laparoscopic colorectal surgery; 2. Tumor staging ≤ T3 without invasion of surrounding organs; 3. No abdominal seeding or distant organ metastasis; 4. Clear and complete imaging data (CT, pelvic MRI) that can be processed by a computer; 5. Feasible evaluation and determination for obtaining specimens through the rectal channel during preoperative and intraoperative assessments. Exclusion Criteria: 1. Contraindications for laparoscopic colorectal surgery; 2. Tumor staging is T4, or there are cancer nodules; 3. Presence of metastasis or distant organ metastasis; 4. Incomplete imaging data; 5. Preoperative intestinal obstruction; 6. Tumor or specimen diameter larger than the transverse diameter of the pelvic outlet; 7. Previous rectal radiotherapy; 8. Unsuitable evaluation and determination for obtaining specimens through the rectal channel during preoperative and intraoperative assessments.