Hepatic Portal System

The hepatic portal system begins in the capillaries of the digestive organs and ends in the portal vein. Consequently, portal blood contains substances absorbed by the stomach and intestines. Portal blood is passed through the hepatic lobules where nutrients and toxins are absorbed, excreted or converted.

Restriction of outflow through the hepatic portal system can lead to portal hypertension. Portal hypertension is most often associated with cirrhosis. Patients usually present with splenomegaly, ascites, GI bleeding and/or portal systemic encephalopathy.

The consequences of portal hypertension are due to portal systemic anastomosis formed by the body as an attempt to bypass the obstructed liver circulation. These collateral vessels form along the falciform ligament, diaphragm, spleen, stomach and peritoneum. The collaterals find their way to the renal vein where blood drained from the digestive organs is let into the systemic circulation.