Multicenter Study on Preservation Versus Excision of Denonvilliers Fascia in L-PANP Surgery

Inclusion Criteria: 1. Male, 20 \< age (years) \< 71, informed consent; 2. Pathological diagnosis of rectal adenocarcinoma; 3. Tumors from anal edge 6 \~ 12 cm (measured by rigid proctoscope); 4. Preoperative staging T1-4 (T1-2 for anterior rectal wall) N0-2M0 rectal cancer (AJCC- 7th); 5. R0 TME surgical results is expected; 6. Preoperative ECOG physical status score 0/1; 7. Preoperative ASA grade I \~ III; 8. Normal urinary function (Bladder residual urine\<100ml), normal erection function (IIEF-5\>21) and ejaculation function grading as I level. Exclusion Criteria: 1. Complicated with acute ileus, perforation or hemorrhage; 2. Tumors with extensive invasion of surrounding tissues, TME not applicable; Imaging examination in regional integration intumescent lymph nodes (maximum diameter 3 cm or higher); 3. With other malignant diseases or with other malignant disease within 5 years; With other diseases need surgery; 4. A history of abdominal and pelvic major operation; 5. People with severe mental illness, or cannot be evaluated due to cultural or psychological factors; 6. No sexual life; 7. Critical organ dysfunction, unbearable surgery; 8. Unstable angina, myocardial infarction, cerebral infarction or hemorrhage within 6 months; 9. Systemic corticosteroids or immunosuppressive medication history within 1 month; 10. Pre-existent true incontinence or severe stress urinary incontinence. Exit criteria: 1. Confirmed as M1 during or after operation; 2. Conversion to abdominoperineal resection (APR) 3. Postoperatively confirmed as invading rectal intrinsic fascia, or T3 for anterior rectal wall; 4. Intraoperative confirmed regional lymph node fusion conglobation cannot ensure R0 resection; 5. Infiltrating major blood vessel and unresectable; 6. Intraoperative finding other diseases need simultaneous surgery; 7. Preoperative emergent severe complications, cannot carry out the study treatment; 8. Emergency surgery is needed; 9. Into this study, at any stage of the initiative exit or discontinue treatment; Prove to implement the healer violates this research plan.