Rectosacral Fascia

fascia rectosacralis

A condensation of the presacral fascia attaching the posterior rectal fascia to the anterior sacrum at the S4 level (Waldeyer's fascia or rectosacral ligament).

Region: Abdomen

Biomechanics

Function & Actions

Anchors the rectum to the sacrum posteriorly, preventing pelvic descent, and provides the posterior boundary of the mesorectal envelope.

Clinical Relevance

Clinical Notes

Waldeyer's fascia is divided sharply during total mesorectal excision (TME) to complete the posterior mesorectal dissection to the anorectal junction. Failure to recognise this structure leads to either entering the presacral space (bleeding from presacral veins) or breaching the mesorectum (positive circumferential margin). The presacral veins are particularly vulnerable at the S4 level.

Pathology

Common Injuries & Conditions

Presacral Venous Bleeding at Waldeyer's Fascia Level

Division of Waldeyer's fascia in the wrong plane tears the presacral venous plexus producing life-threatening presacral haemorrhage, managed by bone wax or haemostatic tacks over the sacral foramina.