Relationships between pelvic nerves and levator ani muscle for posterior sacrocolpopexy: an anatomic study

The placement of posterior mesh during pelvic organ prolapse laparoscopic surgery has been incriminated as responsible for postoperative adverse outcomes such as digestive symptoms, chronic pelvic pain, and sexual dysfunction. These complications may be related to neural injuries that occur during the fixation of the posterior mesh on the levator ani muscle.

The aim of our study was to describe the course of the autonomic nerves of the pararectal space and their anatomical relationship with the posterior mesh fixation zone on the levator ani muscle.

Twenty hemi-pelvis specimens from 10 fresh female cadavers were dissected. We measured the distance between the posterior mesh fixation zone on the levator ani, and the nearest point of adjacent structures: the hypogastric nerve, inferior hypogastric plexus, uterosacral ligament, uterine artery, and ureter. Measurements were repeated starting from the inferior hypogastric plexus.

Nerve fibers of the inferior hypogastric plexus spread out systematically above the superior aspect of the levator ani muscle. Median distance from the posterior mesh fixation zone and the inferior hypogastric plexus was around 2.8 (range 2.1-3.5) cm.

The inferior hypogastric plexus lies above the superior aspect of the levator ani muscle. A short distance between the posterior mesh fixation zone on the levator ani muscle and inferior hypogastric plexus could explain in part postoperative digestive symptoms. These observations support the development of nerve-sparing procedures for posterior mesh placement in the context of pelvic organ prolapse repair and suggest that postoperative complications could be improved by changing the fixation zone.