Rationale of pelvic autonomic nerve preservation in rectal cancer surgery based on immunohistochemical study
PURPOSE Total mesorectal excision contains two different procedures: autonomic nerve preservation, and autonomic nerve sacrifice. It is unclear whether autonomic nerve preservation is suitable curative procedure. We clarify the significance of autonomic nerve preservation for an advanced lower rectal cancer. METHODS All 403 patients curatively resected between 1975 and 1999 were clinicopathologically studied. Between 1975 and 1984, all patients routinely received total mesorectal excision without autonomic nerve preservation (TME-P(-) group). Since 1985, total mesorectal excision with autonomic nerve preservation has been performed in 81 percent of patients (TME-P(+) group). The remaining patients received TME-P(-) because of suspicious invasion to autonomic nerve plexus. All clinical and pathologic data were entered into a computer database. Long-term follow-up was used to analyze the oncologic and functional results of TME-P(+) group compared with TME-P(-) group. RESULTS The follow-up rate was 98.1 percent. In either Dukes A+B or Dukes C disease, the TME-P(+) group did not increase local recurrence or decrease ten-year disease-free survival compared with the TME-P(-) group of Period 1975 to 1984. The TME-P(-) group of Period 1985 to 1999 had the highest distant metastasis and the lowest survival rates than any other groups. Urinary or sexual function was well preserved in the TME-P(+) group. CONCLUSIONS Autonomic nerve preservation is oncologically and functionally excellent and suitable for almost all patients with advanced lower rectal cancer. Intensive chemotherapy is needed for patients whose autonomic nerves were killed in suspicion of nerve invasion.