Define Retroperitoneal and Give an Example of a Retroperitoneal Organ

Retroperitoneal space
Horizontal plane through the kidneys, showing subdivisions of the retroperitoneal space. The anterior and posterior pararenal spaces have been exaggerated to provide representation of their relation to other retroperitoneal structures.
Human kidneys viewed from behind with spine removed
Details
Identifiers
Latin	spatium retroperitoneale
MeSH	D012187
TA98	A10.1.01.002
TA2	3814
FMA	15080
Anatomical terminology [edit on Wikidata]

The retroperitoneal space (retroperitoneum) is the anatomical space (sometimes a potential space) 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.^[1]

This is different from organs that are not retroperitoneal, which have peritoneum on their posterior side and are suspended by mesentery in the abdominal cavity.

The retroperitoneum can be further subdivided into the following:^[2]

• Perirenal (or perinephric) space
• Anterior pararenal (or paranephric) space
• Posterior pararenal (or paranephric) space

Retroperitoneal structures [edit]

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
  • anal canal
• Secondarily retroperitoneal, meaning the structures initially were suspended in mesentery and later migrated behind the peritoneum during development^[3]
  • the duodenum, except for the proximal first segment, which is intraperitoneal^[4]
  • ascending and descending portions of the colon (but not the transverse colon, sigmoid and the cecum)
  • pancreas, except for the tail, which is intraperitoneal

Subdivisions [edit]

Transverse section, showing the relations of the capsule of the kidney. (Peritoneum is labeled at center right.)

Perirenal space

It is also called the perinephric space. Bounded by the anterior and posterior leaves of the renal fascia. It contains the following structures:

• Adrenal gland
• Kidney
• Renal vessels
• Perirenal fat, which is also called the "adipose capsule of the kidney" and may be regarded as being part of the renal capsule^[5]

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 ("pararenal fat"), and is also called the "paranephric body", or "pararenal fat body".

Clinical significance [edit]

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

It is also possible to have a neoplasm in this area, more commonly a metastasis; or very rarely a primary neoplasm. The most common type is a sarcoma followed by lymphoma, extragonadal germ cell tumor, and Gastrointestinal stromal tumor/GIST.^[6] Examples of tumors include

• • Primary retroperitoneal carcinoma
  • Pseudomyxoma peritonei
  • Examples of sarcomas include:
  • Soft-tissue sarcoma
    • liposarcoma
    • leiomyosarcoma
    • Undifferentiated pleomorphic sarcoma, a clinically distinct sarcoma of the area

See also [edit]

• Intraperitoneal

References [edit]

1. ^ Gray's Anatomy for Students, 2nd Ed. 2010. Pg. 251
2. ^ Ryan, Stephanie; McNicholas, Michelle; Eustace, Stephen (2004). Anatomy for Diagnostic Imaging. Sydney: Saunders. p. 191. ISBN978-0-7020-2620-1.
3. ^ Kyung Won Chung (2005). Gross Anatomy (Board Review). Hagerstown, MD: Lippincott Williams & Wilkins. p. 256. ISBN0-7817-5309-0.
4. ^ K. L. Moore; A. F. Dalley; A. M. R. Agur (2005). Clinically Oriented Anatomy . Hagerstown, MD: Lippincott Williams & Wilkins. pp. 1209. ISBN0-7817-3639-0.
5. ^ University of Michigan - Lab Manual - Kidneys & Retroperitoneum
6. ^ Raval, Bharat; Pollock, Raphael E.; Guadagnolo, Ashleigh; Patel, Shreyaskumar (1 January 2012). "Chapter 23 - Primary Retroperitoneal Tumors". Oncologic Imaging: A Multidisciplinary Approach. W.B. Saunders. pp. 403–421.

Define Retroperitoneal and Give an Example of a Retroperitoneal Organ

Source: https://en.wikipedia.org/wiki/Retroperitoneal_space

Share this post