CorpusHuman Anatomy
DigestiveSpace

Retroperitoneal space

Spatium retroperitoneale

Also known as: retroperitoneum, retroperitoneal organs, SAD PUCKER

The retroperitoneum is the space between the posterior parietal peritoneum and the posterior abdominal wall. It holds the great vessels, kidneys and several digestive organs that are fixed behind the peritoneum.

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Overview

Fascial planes divide the retroperitoneum into three compartments. The anterior pararenal space contains the pancreas, duodenum (parts 2–4) and ascending and descending colon. The perirenal space, inside the renal (Gerota) fascia, contains the kidneys, suprarenal glands, renal vessels and perirenal fat. The posterior pararenal space contains only fat. The aorta, IVC, para-aortic nodes, cisterna chyli, sympathetic trunks and ureters also run in the retroperitoneum.

Primarily retroperitoneal organs developed behind the peritoneum and never had a mesentery: kidneys, ureters, suprarenals, aorta and IVC, and the oesophagus. Secondarily retroperitoneal organs originally hung on a mesentery that later fused with the posterior parietal peritoneum, forming fusion fascia (of Toldt or Treitz). These are the duodenum (except the cap), the pancreas (except the tail), and the ascending and descending colon. Surgeons reopen these avascular fusion planes to mobilise them, for example in the Kocher manoeuvre for the duodenum and medial visceral rotation.

Location

Posterior abdominal wall, behind the parietal peritoneum, from the diaphragm to the pelvic brim.

Parts & subdivisions

  1. Anterior pararenal space
    Pancreas, duodenum (2–4), ascending and descending colon.
  2. Perirenal space
    Kidneys, suprarenals and perirenal fat within the renal fascia.
  3. Great vessels
    Abdominal aorta and IVC.

Function

  • Anchors and protects the posterior abdominal organs.
  • Conduit for the great vessels, nerves and lymphatic trunks.

Clinical significance

Retroperitoneal haemorrhage

Causes include a ruptured abdominal aortic aneurysm, trauma, anticoagulation, and haemorrhagic pancreatitis, which can produce flank bruising (Grey Turner sign). Because it does not enter the peritoneal cavity, it may cause little peritonism and only back or flank pain.

Missed retroperitoneal duodenal injury

Blunt trauma (for example from a steering wheel or bicycle handlebar) can rupture the retroperitoneal duodenum. Early signs are subtle, and imaging shows retroperitoneal air.

Mnemonics

SAD PUCKER

Suprarenal glands · Aorta/IVC · Duodenum (2nd–4th parts) · Pancreas (except tail) · Ureters · Colon (ascending, descending) · Kidneys · Esophagus · Rectum (lower two-thirds).

Compiled from standard anatomy and physiology references — see the Digestive System sources. For education only; not medical advice.