Urinary and sexual dysfunctions are among the most common complications in rectal cancer surgery. The aim of this study was to investigate the protective effect of laparoscopic functional total mesorectum excision (FTME) on urinary and sexual function in male patients with mid-low rectal cancer. This is a prospective, single-arm, multicenter, uncontrolled, clinical study in 88 eligible subjects with mid-low rectal cancer. After informed consent, eligible patients will be performed laparoscopic FTME surgery. Patients' demographic, operative detail, postoperative outcomes and follow-up will be recorded prospectively.

Previously, our studies have demonstrated the presence of nerve plane in laparoscopic rectal cancer surgery, which was the overlying tiny membranous tissue including the nerves, the adipose tissue, and the extremely tiny capillaries around the nerve. As a consequence, the concept of nerve plane-oriented functional total mesorectal excision (FTME) was proposed as an optimal surgical procedure about pelvic autonomic nerve preservation in rectal cancer surgery. Following the TME principles, the surgical procedure of FTME was guided by the nerve plane and dissected between the proper fascia of the rectum and nerve plane (the first gap), which could ensure completeness of the nerve plane and the proper fascia of the rectum. This surgical procedure not only ensures radical resection but also protects PAN better, and the investigators also showed the difference between routine TME and FTME in our previous study, which included inferior mesenteric plexus preservation, station 253 nodes dissection, existence of the first gap, Waldeyer's fascia and Denonvillier's fascia (DVF) preservation, neurovascular bundles preservation, and completeness of mesorectum and nerve plane. Currently, it was a lack of higher-level evidence-based evidence to confirm the protective effect of laparoscopic FTME on urinary and sexual function in male patients with mid-low rectal cancer. In the present study, the investigators performed the prospective, single-arm, multicenter, uncontrolled clinical study, eligible patients will be performed laparoscopic FTME surgery. Postoperative sexual function, urinary function, complications, quality of life, recurrence rate, recurrence patterns, disease-free survival, and overall survival will be recorded prospectively. The results of the patients will be assessed to validate postoperative functional outcomes and oncologic outcomes of laparoscopic FTME surgery.

Inclusion Criteria:

1. Male, 18-70 years of age, informed consent;
2. Tumors from anal edge 6 ~ 12 cm (measured by rigid proctoscope);
3. Rectal cancer confirmed pathologically by endoscopic biopsy;
4. Preoperative cT1-3aN0M0 stage (ESMO, 2013);
5. Ro resection is expected;
6. Normal urinary function, normal erection function and ejaculation function grading as I level;

Exclusion Criteria:

1. History of abdominal and pelvic major surgery;
2. Emergency surgery is needed due to the complication (bleeding, obstruction, or perforation) caused by rectal cancer;
3. Pelvic or distant metastasis;
4. Neoadjuvant radiotherapy or chemoradiotherapy;
5. No sexual life;