Retroperitoneal Space - Retroperitoneal Structures

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:
  • urinary
    • adrenal glands
    • kidneys
    • ureter
    • bladder
  • circulatory
    • aorta
    • inferior vena cava
  • digestive
    • esophagus (thoracic part, part inside abdominal cavity is intraperitoneal)
    • rectum (part, lower third is extraperitoneal)

• Secondarily retroperitoneal:
  • 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 or the cecum)

A useful mnemonic to aid recollection of the abdominal retroperitoneal viscera is SAD PUCKER, or DUKE CRAPS:

• S = Suprarenal glands (aka the adrenal glands)
• A = Aorta/IVC
• D = Duodenum (second and third segments )
• P = Pancreas (tail is intraperitoneal)
• U = Ureters
• C = Colon (only the ascending and descending colons, as transverse and sigmoid retain mesocolon)
• K = Kidneys
• E = Esophagus
• R = Rectum

Another mnemonic going along with SAD PUCKER is 112 212111, this correlating to which ones are Primarily (1) or Secondarily (2) Retroperitoneal.