Corpus: Retroperitoneal

Retroperitoneal means "located behind the peritoneal cavity" or "located behind the peritoneum", i.e. in the spatium retroperitoneale (retroperitoneal space).

There are 3 anatomical forms of retroperitoneal location:

• Primary retroperitoneal organs are located behind the peritoneal cavity and have also developed there during the embryonic period, such as the kidneys, ureters, adrenal glands, aorta and inferior vena cava.
• Secondary retroperitoneal organs are organs that were initially located intraperitoneally but then adhered to the dorsal abdominal wall in the course of further embryonic development. They are only covered ventrally by the peritoneum. These include
  • Duodenum: Pars descendens, Pars horizontalis and Pars ascendens, but not the intraperitoneal Pars superior
  • Pancreas (pancreas)
  • Colon ascendens, descendens
  • Rectum fixum
• Tertiary retroperitoneal is a special case of retroperitoneal location that only applies to a part of the duodenum, the pars tecta duodeni. It is located secondarily retroperitoneal due to development, but is additionally overlaid by the ascending mesocolon during further development.

In everyday clinical practice, only the general term "retroperitoneal" is generally used.

see also: intraperitoneal and extraperitoneal