Posterior Rectus Sheath Tendinous Layer

lamina posterior vaginae musculi recti abdominis

The posterior rectus sheath is formed above the arcuate line by the posterior laminae of the internal oblique and transversus abdominis aponeuroses. Below the arcuate line the posterior sheath is absent, replaced only by transversalis fascia. The posterior sheath provides the backstop for rectus abdominis muscle function.

Region: Abdomen

Clinical Relevance

Clinical Notes

The posterior rectus sheath is the surgical boundary in Rives-Stoppa and IPOM hernia repairs, where mesh is placed in the retrorectus space between the muscle and its posterior sheath. Posterior sheath fenestration is the key step separating the retrorectus from the preperitoneal space in component separation hernia repair. The arcuate line marks the inferior limit of the posterior sheath.

Pathology

Common Injuries & Conditions

Posterior Sheath Haematoma

Rectus sheath haematoma below the arcuate line extending unrestricted in the preperitoneal space from inferior epigastric artery injury in anticoagulated patients, producing a rapidly expanding pelvic mass requiring angiographic embolisation.