The retroperitoneum (adj. retroperitoneal) is the anatomical space behind (retro) the abdominal cavity. It has no specific delineating anatomical structures.

Retroperitoneal bleeding, such as from a ruptured aortic aneurysm shows as Grey Turner's sign (flank bruising).

Retroperitoneal structures

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Structures that lie behind the peritoneum and are thus termed "retroperitoneal". These include:

• kidneys
• bladder
• portions of the duodenum
• portions of the colon
• inferior vena cava
• part of the pancreas

Role in disease

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• Retroperitoneal fibrosis

Physiology

Retroperitonealraum | Retroperitoneum