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.

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