Overview
- Parasympathetic nerves originating from S2-S4
- Also called the Nervi erigentes
- Join the Inferior hypogastric plexus along with the right and left hypogastric nerves from the Superior hypogastric plexus (SNS)
- Anterior to the aortic bifurcation extending inferiorly between the common iliac arteries and along the left common iliac vein and median sacral vessels
- Origin
- Pelvic splanchnic branches (parasympathetic) from the right and left hypogastric nerves via the inferior hypogastric plexus
- Lumbar splanchnic branches (sympathetic)
- Nerves from the aorticorenal plexus also contribute
- Gives origin to a complex network of small branches and the left and right hypogastric nerves which extend inferiorly to the inferior hypogastric plexuses
- Supplies large bowel distal to the left third of the transverse colon, ureters, gonads and the iliac vessels
- Mixed PS and S nerves
- From sacral promontory, part distally and run on pelvic side walls (male ejaculation)
- Nervi erigentes lie anterolaterally between seminal vesicles and prostate (male erection). Avoid clamping here.
- For posterior tumours, can dissect immediately posterior to Denonvilliers’ fascia/septum to avoid nerve injury.
- For anterior tumours, Denonvillier’s fascia should be removed, however nerves at higher risk.
