Common Causes of Portal Vein Thrombosis

Neonates

Umbilical stump infection, or omphalitis (spread via the umbilical vein to the portal vein)

Congenital portal vein abnormalities (less common)

Congenital abnormalities of the portal vein usually accompany congenital defects elsewhere.

Older children

Pylephlebitis

In acute appendicitis, infection enters the portal system; the vascular infection/inflammation then triggers thrombosis.

Adults

Surgery (eg, splenectomy)

Hypercoagulable states (eg, myeloproliferative disorder, protein C deficiency or protein S deficiency, pregnancy)

Cancer (eg, hepatocellular or pancreatic carcinoma, renal cancers or adrenal cancers)

Cirrhosis

Trauma

Possibly portal hypertension causing congestion and stasis