The inferior hypogastric plexus is the principal autonomic plexus of the pelvis, formed bilaterally by the superior hypogastric plexus descending hypogastric nerves from above, the sacral sympathetic trunk fibres from the sacral ganglia, and the pelvic splanchnic nerves (S2-S4) carrying parasympathetic preganglionic fibres. It lies on the lateral walls of the rectum and bladder and distributes mixed autonomic fibres to all pelvic organs including the bladder, rectum, uterus, vagina, prostate, and erectile tissue.
The inferior hypogastric plexus and its rectal branches lying posterolateral to the rectum are at significant risk during total mesorectal excision (TME) for rectal cancer. Injury produces bladder dysfunction, sexual dysfunction (erectile dysfunction in males, dysorgasmia in females), and defaecatory disorders. Nerve-sparing TME maintains surgical planes immediately adjacent to the mesorectal fascia to avoid plexus injury. The plexus is also injured during radical hysterectomy and prostatectomy.
Division of the inferior hypogastric plexus during rectal cancer surgery produces bladder areflexia requiring catheterisation, erectile dysfunction in males, and female sexual dysfunction, motivating nerve-sparing techniques that preserve the plexus by sharp dissection in the precise TME plane.
Sympathetic denervation of the bladder neck through injury to the superior hypogastric plexus or hypogastric nerves causes failure of bladder neck closure during ejaculation, producing retrograde ejaculation, a common complication of anterior lumbar spine surgery and para-aortic node dissection.
