Anatomic relationships of the pelvic autonomic nervous system in female cadavers: clinical applications to pelvic surgery

Background The integrity of the pelvic autonomic nervous system is essential for proper bowel, bladder, and sexual function. Objective The purpose of this study was to characterize the anatomic path of the pelvic autonomic system and to examine relationships to clinically useful landmarks. Study Design Detailed dissections were performed in 17 female cadavers. Relationships of the superior hypogastric plexus to aortic bifurcation and midpoint of sacral promontory were examined; the length and width of plexus was documented. Path and width of right and left hypogastric nerves were recorded. The origin and course of the pelvic splanchnic nerves were documented. Individual nerve tissue that contributed to the inferior hypogastric plexus was noted. Relative position of nerves to arteries, viscera, and ligaments was documented. In a subset of specimens, biopsy specimens were obtained to confirm gross findings by histologic analysis. Descriptive statistics were used for data analyses and reporting. Results In all specimens, the superior hypogastric plexus was embedded in a connective tissue sheet within the presacral space, just below the peritoneum. In 14 of 17 specimens (82.4%), the plexus formed a median distance of 21.3 mm (range, 9–40 mm) below aortic bifurcation; in the remaining specimens, it formed a median distance of 25.3 mm (range, 20.5–30 mm) above bifurcation. In 58.8% of specimens, the superior hypogastric plexus was positioned to the left of midline. The median length and width of the plexus was 39.5 (range, 11.5–68) mm and 9 (range, 2.5–15) mm, respectively. A right and left hypogastric nerve was identified in all specimens and formed a median distance of 23 mm (range, 5–32 mm) below the promontory. The median width of the hypogastric nerve was 3.5 mm (range, 3–4.5 mm) on the right and 3.5 mm (range, 2–6.5 mm) on the left. The median distance from midportion of uterosacral ligament to the closest nerve branch was 0.5 mm (range, 0-4.5 mm) on right and 0 mm (range, 0-27.5 mm) on left. In all specimens, the inferior hypogastric plexus was formed by contributions from the hypogastric nerves and branches from S3 and S4. In 47.1% of hemipelvises, S2 branches contributed to the plexus. The sacral sympathetic trunk contributed to the plexus in 16 of 34 hemipelvises where this structure was identified. The inferior hypogastric plexus formed 1–3 cm lateral to the rectum and upper third of the vagina. From this plexus, 1–3 discrete branches coursed deep to