Retroperitoneal space

Retroperitoneal space
Transverse section, showing the relations of the capsule of the kidney. (Peritoneum is labeled at center right.)
Human kidneys viewed from behind with spine removed
Details
Latin	spatium retroperitoneale
Identifiers
Dorlands /Elsevier	s_16/12746619
TA
TH	{{#property:P1694}}
TE	{{#property:P1693}}
FMA	{{#property:P1402}}
Anatomical terminology [[[d:|edit on Wikidata]]]

The retroperitoneal space (retroperitoneum) is the anatomical space (sometimes a potential space) in the abdominal cavity behind (retro) the peritoneum. It has no specific delineating anatomical structures. Organs are retroperitoneal if they have peritoneum on their anterior side only. Structures that are not suspended by mesentery in the abdominal cavity and that lie between the parietal peritoneum and abdominal wall are classified as retroperitoneal.

The retroperitoneum can be further subdivided into the following:

• Perirenal space
• Anterior pararenal space
• Posterior pararenal space

Retroperitoneal structures

Structures that lie behind the peritoneum are termed "retroperitoneal". Organs that were once suspended within the abdominal cavity by mesentery but migrated posterior to the peritoneum during the course of embryogenesis to become retroperitoneal are considered to be secondarily retroperitoneal organs.

• Primarily retroperitoneal, meaning the structures were retroperitoneal during the entirety of development:
  • urinary
    • adrenal glands
    • kidneys
    • ureter
  • circulatory
    • aorta
    • inferior vena cava
  • digestive
    • esophagus (thoracic part, part inside abdominal cavity is intraperitoneal)
    • rectum (part, lower third is extraperitoneal)
• Secondarily retroperitoneal, meaning the structures initially were suspended in mesentery and later migrated behind the peritoneum during development:
  • the head, neck, and body of the pancreas (but not the tail, which is located in the splenorenal ligament)
  • the duodenum, except for the proximal first segment, which is intraperitoneal
  • ascending and descending portions of the colon (but not the transverse colon, sigmoid or the cecum)

Subdivisions

Perirenal Space

Bounded by the anterior and posterior leafs of the renal fascia. It contains the following structures:

• Adrenal gland
• Kidney
• Renal vessels

Anterior pararenal space

Bounded by the posterior layer of peritoneum and the anterior leaf of the renal fascia. It contains the following structures:

• Pancreas
• Ascending and descending colon
• duodenum

Posterior pararenal space

Bounded by the posterior leaf of the renal fascia and the muscles of the posterior abdominal wall. It contains only fat.

Clinical significance

Bleeding from a blood vessel or structure in the retroperitoneal such as the aorta or inferior vena cava into the retroperitoneal space can lead to a retroperitoneal hemorrhage.

• Retroperitoneal fibrosis
• Retroperitoneal lymph node dissection

See Also

• Intraperitoneal