Cadaveric Study Of Pelvic Autonomic Plexus In The Male Pelvis And Its Clinical Significance In Rectal Surgery

Background: The total mesorectal excision (TME) often cause a incidence of pelvic organ dysfunction, even though the autonomic nerves preservation was performed. Undoubtedly, maintenance of integral functions after surgery for rectal carcinoma relies on the best understanding of the pelvic neural structures. The purpose of this cadaver study was to highlight the organization and localization of the pelvic autonomic plexus and the secondary pelvic visceral nervous plexuses.To test the feasibility of laparoscopic approach in performing the simultaneous pelvic autonomic nerve preservation during standard anterior resection of rectal cancer. To assess the succession of laparoscopic total mesorectal excision with pelvic autonomic nerve preservation in terms of voiding and sexual function in males with rectal cancer.Methods:Ten cadavers were dissected to observe the courses of the pelvic plexus and distribution of its branches including the seconary pelvic visceral nervous plexuses. The transverse diameter and length, as well as the distances of origin of the secondary pelvic autonomic plexuese to the sacral promontory, pubic symphysis and lateral wall of rectum were measured and analyzed statistically. Two cadavers were sliced horizontally. Specimens were harvested and processed for light microscopy and immunohistochemistry to analyze the types of nerves and their localization. 24 male patients meeting appropriate eligibility criteria were recruited for the present study.12 patients underwent laparoscopic pelvic autonomic nerve preservation total mesorectal excision, The other 12 patients underwent open total mesorectal excision(control). The genitourinary function was evaluated on the basis of validated questionnaires including International Prostate Symptom Score (IPSS), and International Index of Erectile Function (IIEF).Results: The right hypogastric nerve was longer and thicker than left one .Beside of anatomosis with the pelvic plexus, the inferior mesentric plexus directly gave off a fiber to participat in the formation of the pelvic plexus. Three specimens in 10 specimens were found the inferior mesentric plexus directly gave off a fiber to participat in the formation of the pelvic plexus, about 30%. Excluding the distances from the origin of rectal plexus to sacral pomontory , no side differences were found origin of vescial plexus, and rectal pelxus to the sacral promontory, pubic symphysis and to the lateral wall of rectum. Furthermore, the main fibers of left vesical plexus and prostatic plexus were thicker than right one, transverse diameter of right vesical 1.12±0.11 mm,length 15.3±7.89 mm;transverse diameter of left 1.41±0.24 mm,length 18.2±3.77 mm. transverse diameter of right prostatic plexus main fibers 1.15±0.24 mm,length 15.1±9.50 mm;transverse diameter of left 1.50±0.24 mm,length 20.4±6.60 mm. and main fiber of the rectal plexus was shorter and thinner than right one. transverse diameter of righ trectal plexus main fiber 1.07±0.22 mm,length 24.5±11.2 mm;transverse diameter of left 0.86±0.18 mm,length 15.2±2.66 mm.The pelvic plexus was differed in craniaoanal diameter and dorsovental diameter from right to left. In addition, the fiber number from the secondary pelvic visceral plexuses to specific organs was varied , while the stage numbers were constant in both sides. A total of 24 patients (group 1 LTME-ANP laparoscopic autonomic nerve preserving total mesorectal excision n =12; group 2 (control) OTME open total mesorectal excision n =12) with good baseline genitourinary function were operated on with the intent of total preservation of pelvic autonomic nerves and curative resection of rectal cancer. The patients were prospectively followed (median time of follow-up 6 months). In patients with a successful nerve-preserving surgery (83.3%, 12), 24 patients completed the evaluation of urinary function. The median duration for indwelling urine Foley catheter was respectively LTME-ANP 3.0 days (range, 1.0–7.6 days); OTME 5 (range, 3–8 days). The voiding function after operation of LTME-ANP was better than OTME( LTME-ANP Qax(ml/s), Vcomp(ml), RV(ml) was respectively 13.7±7, 163±78, 8.1±11.4; OTME 11.5±6.3, 143±69, 12.2±11.9). Total IPSS (LTME-ANP 8.3±5.6, OTME 10.7±7.3). Before and after surgery, there were no significant changes of IPSS scores in the present patient series. Sexual function of LTME-ANP and OTME after operation were both decreased, and LTME-ANP was better than OTME.Conclusion: These finding suggest that quantitive localization of the secondary pelvic plexusese via some landmarks is helpful and feasible to avoid the pelvic autonomic nerve damage, and it will ssupplies base on morphology to the total mesorectal excision (TME). Under laparoscopy, we can clearly identify and preserve the pelvic autonomic nerves to retain genitourinary function in most patients undergoing oncologic resection of rectal cancer. As advaced technical of surgery is available, patients undergoing oncologic resection of rectal cancer would be elevated their quality of life non-consideration economy.