Transanal Total Mesorectal Excision vs Robotic Total Mesorectal Excision

TME remains standard treatment for rectal cancer. Both Robotic TME and taTME are innovative surgical techniques with potential advantages in low rectal cancer. To date, no clinical studies have directly compared the conversion and complication rates between taTME and RTME in this population. Therefore, the investigators propose to conduct a prospective, randomized, parallel-controlled clinical trial comparing taTME with RTME for low rectal cancer, aiming to provide high-level evidence for surgical decision-making and benefit more patients.

Inclusion Criteria:Newly diagnosed patients aged 18-75 years. Pathologically confirmed adenocarcinoma (tubular, papillary, mucinous, or signet-ring). Tumor ≤7 cm from anal verge (MRI or DRE). Clinical stage T1-T3, N+, M0 (AJCC 8th ed.), suitable for sphincter-preserving TME. ASA score I-III. ECOG performance status 0-1. Informed consent obtained. \- Exclusion Criteria: Synchronous/metachronous colorectal cancers, local recurrence, or distant metastases. Bowel obstruction, perforation, bleeding requiring emergency surgery. Involvement of sphincter or adjacent organs requiring Inter-sphincter Resection (ISR). Poor preoperative anal function/incontinence. IBD or familial adenomatous polyposis (FAP). Pregnancy or lactation. Severe psychiatric illness. Other malignancies within 5 years. Severe comorbidities or infections making surgery intolerable. Judged unsuitable by investigator.