Portacaval anastomosis

A portacaval anastomosis (also known as portal systemic anastomosis or portal caval system) is a specific type of anastomosis that occurs between the veins of portal circulation and those of systemic circulation. The lower end of esophagus is one of the important sites for the portosystemic anastomosis . In portal hypertension as in the case of cirrhosis of liver the anastomosis opens and forms venous dilatation called esophageal varices. Their rupture causes severe and dangerous haematesis (hematemesis). Specific types include:

Region	Name of clinical condition	Portal circulation	Systemic circulation
Esophageal	Esophageal varices	Esophageal branch of left gastric vein	Esophageal branches of Azygos vein
Rectal	Hemorrhoids	Superior rectal vein	Middle rectal veins and inferior rectal veins
Paraumbilical	Caput medusae	Paraumbilical veins	Superficial epigastric vein
Retroperitoneal	(no clinical name)	Right colic vein, middle colic vein, left colic vein	Renal vein, suprarenal vein, paravertebral vein, and gonadal vein
Intrahepatic	Patent ductus venosus	Left branch of portal vein	Inferior vena cava

It can be one of the conditions caused by portal hypertension. A useful mnemonic is that portal hypertension causes problems in the butt, the gut, and caput. A dilated inferior mesenteric vein may or may not be related to portal hypertension.

References

• Compendio de Anatomía humana. Testut- LaTarjet