Portacaval anastomosis

Portacaval anastomosis
Other namesPorto-systemic anastomosis Portal caval system

A portocaval anastomosis or Porto-systemic anastomosis is a specific type of anastomosis that occurs between the veins of the portal circulation and those of the systemic circulation. When there is a blockage of the portal system, portocaval anastomosis enable the blood to still reach the systemic venous circulation.The inferior end of the esophagus and the superior part of the rectum are potential sites of a harmful portacaval anastomosis.[1]

In portal hypertension, as in the case of cirrhosis of the liver, the anastomoses become congested and form venous dilatations. Such dilatation can lead to esophageal varices and anorectal varices. Caput medusae can also result.[2]

Presentation

Clinical presentations of portal hypertension include:

RegionName of clinical conditionPortal circulationSystemic circulation
EsophagealEsophageal varicesEsophageal branch of left gastric veinEsophageal branches of azygos vein
RectalRectal varicesSuperior rectal veinMiddle rectal veins and inferior rectal veins
ParaumbilicalCaput medusaeParaumbilical veinsSuperficial epigastric vein
RetroperitonealSplenorenal shunt[3]Splenic veinRenal vein, suprarenal vein, paravertebral vein, and gonadal vein
(no clinical name)[4] Right colic vein, middle colic vein, left colic vein Retroperitoneal veins of Retzius
Intrahepatic Hepatic pseudolesions[5] Perihepatic veins of Sappey Superior epigastric vein
Patent ductus venosusLeft branch of portal veinInferior vena cava

A dilated inferior mesenteric vein may or may not be related to portal hypertension. Other areas of anastomosis include the bare area of the liver as it connects to the diaphragm, the posterior portion of the gastrointestinal tract as it touches the posterior abdominal wall, the posterior surface of the pancreas, and the inferior part of the esophagus.

References

  1. ↑ Sato, Takahiro; Akaike, Jun; Toyota, Jouji; Karino, Yoshiyasu; Ohmura, Takumi (2011). "Clinicopathological Features and Treatment of Ectopic Varices with Portal Hypertension". International Journal of Hepatology. 2011: 960720. doi:10.4061/2011/960720. PMC 3170857. PMID 21994879.
  2. ↑ Gray's Anatomy for Students Gray H, Drake R, Vogl W, Mitchell A, Tibbitts R, Richardson P. Philadelphia: Elsevier/Churchill Livingstone; 2010. p. 226
  3. ↑ D'Souza, Donna. "Portal-systemic collateral pathways | Radiology Reference Article | Radiopaedia.org". radiopaedia.org. Retrieved 2016-08-12.
  4. ↑ "Surgicomania: Portal Hypertension". surgicomania.blogspot.co.uk. 2009-11-23. Retrieved 2016-08-12.
  5. ↑ Khader.O.Thabet, Mohammed Al. "Hepatic pseudolesion near falciform ligament | Radiology Reference Article | Radiopaedia.org". radiopaedia.org. Retrieved 2016-08-12.
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