RECONSTRUCTIVE UROLOGY

Topography of the pelvic autonomic nervous system and its potential impact on surgical intervention in the pelvis
Baader B, Herrmann M
Department of Anatomy and Cellular Neurobiology, University of Ulm, Ulm, Germany
Clin Anat. 2003; 16: 119-30

• Bladder, bowel, and sexual dysfunction caused by iatrogenic lesions of the inferior hypogastric plexus (IHP) are well known and commonly tolerated in pelvic surgery. Because the pelvic autonomic nerves are difficult to define and dissect in surgery, and their importance often ignored, we conducted a gross anatomic study of 90 adult and four fetal hemipelves. Using various non-surgical approaches, the anatomic relations and pathways of the IHP were dissected. The IHP extended from the sacrum to the genital organs at the level of the lower sacral vertebrae. It originated from three different sources: the hypogastric nerve, the sacral splanchnic nerves from the sacral sympathetic trunk (mostly the S2 ganglion), and the pelvic splanchnic nerves, which branched primarily from the third and fourth sacral ventral rami. These fibers converge to form a uniform nerve plate medial to the vascular layer and deep to the peritoneum. The posterior portion of the IHP supplied the rectum and the anterior portion of the urogenital organs; nerve fibers traveled directly from the IHP to the anterolateral wall of the rectum and to the inferolateral and posterolateral aspects of the urogenital organs. The autonomic supply from the IHP was supplemented by nerves accompanying the ureter and the arteries. An understanding of the location of the autonomic pelvic network, including important landmarks, should help prevent iatrogenic injury through the adoption of surgical techniques that reduce or prevent postoperative autonomic dysfunction.
  
• Editorial Comment
  A description of the pelvic autonomic nerves system is nothing totally new. However, even after more than a century of pelvic surgery and interventions we still have not clearly straightened out the exact role of autonomic nerve fibres for some of the pelvic organs nor do we know everything about their variability in relation to pelvic organs. Recent papers have shown that autonomic nerve fibres may be responsible for sensory stimuli in the membraneous urethra of male patients after prostatectomy or cystoprostatectomy. Furthermore these nerves regulate contractility and muscle tone in the remnant urethra in female cystectomy patients undergoing an orthotopic neobladder. Urinary retention in patients undergoing rectal surgery may at least in part be caused by irritation or destruction of parasympatetic or sympathetic fibres contributing to the plexus.
  In this paper the authors have demonstrated among other things that the sacral contributions to the pudendal nerve were the same as for the autonomic inferior hypogastric plexus. This brings an old discussion back whereby at least some autonomic nerve functions may be transmitted via the pudendal nerve. Another important message in this paper is that surgeons should be much more aware of nerve sparing techniques during rectal surgery because of its implications to urinary and sexual function of their patients. Clinical anatomy using both new staining techniques and fetal specimens can still yield interesting and sometimes even new aspects regarding pelvic surgery and preservation of life quality without oncological compromise.

Dr. Arnulf Stenzl
Professor and Chairman of Urology
Eberhard-Karls-University Tuebingen
Tuebingen, Germany