The surgical anatomy of the rectum — a review with particular relevance to the hazards of rectal mobilisation

The major complications of rectal surgery that are wholly or partially avoidable by the use of an anatomically based dissection are haemorrhage from presacral veins, perforation of the rectum, damage to pelvic autonomic nerves and inadequate clearance of a rectal cancer. Important technical points in minimising the incidence of these complications are: (1) posterior dissection in the presacral space; (2) entry to this space by sharp dissection immediately posterior to the superior rectal artery; (3) deliberate incision of the rectosacral fascia; (4) anterior dissection posterior to Denonvilliers fascia in benign disease; (5) removal of the entire mesorectum for low rectal cancer. Other anatomical points not widely appreciated are: 1. The middle rectal artery does not run in the lateral ligaments of the rectum, but below them, on levator ani. It reaches the rectum by penetrating Denonvilliers' fascia. 2. The lateral ligaments may contain an accessory middle rectal artery in 25% of cases. 3. The pelvic autonomic nerves are buried in endopelvic fascia on the pelvic side wall, but come to lie close to the anterior aspect of the rectum at the level of the prostate or upper vagina.