Anatomical basis for nerve-sparing radical hysterectomy: immunohistochemical study of the pelvic autonomic nerves

Abstract

Background: Autonomic nerve damage plays a crucial role in the etiology of bladder dysfunction, sexual dysfunction, and colorectal motility disorders that occur after radical hysterectomy. We investigated the extent and nature of nerve damage in conventional and nerve-sparing radical hysterectomy.

Methods: Macroscopical disruption of nerves was assessed through anatomical dissection after conventional and nerve-sparing surgery on five fixed and one fresh cadaver. Immunohistochemical analysis of surgical margins was performed to confirm nerve damage using a general nerve marker (S100) and a sympathetic nerve marker (anti-tyrosine hydroxylase) within sections of biopsies.

Results: Macroscopical dissection showed that in the conventional procedure, transsection of the uterosacral ligaments resulted in disruption of the major part of the hypogastric nerve. After nerve-sparing surgery, only the medial branches of the hypogastric nerve appeared disrupted. Division of the cardinal ligaments in the conventional procedure identified the inferior hypogastric plexus running into the most posterior border of the surgical margin. The anterior part of the plexus was disrupted. Dissection of the nerves after the nerve-sparing procedure showed that this anterior part of the plexus was not involved in the surgical dissection line. Dissection of the vesicouterine ligament disrupted only small nerves on the medial border of the inferior hypogastric plexus in both techniques. Microscopical evaluation of the surgical margins confirmed the macroscopical findings.

Conclusion: Conventional radical hysterectomy results in disruption of a substantial part of the pelvic autonomic nerves. The nerve-sparing modification leads to macroscopic reduction in nerve disruption which is substantiated by microscopical evaluation of surgical margins.