Portal Vein Thrombosis

Common causes vary by age group (see table Common Causes of Portal Vein Thrombosis ). The cause is multifactorial in most cases and unknown in about one-third of cases (1).

Acute portal vein thrombosis is commonly asymptomatic unless associated with another event, such as pancreatitis (the cause), or another complication, such as mesenteric venous thrombosis. Most often, clinical features—splenomegaly (especially in children) and variceal hemorrhage—develop over a period of time secondary to portal hypertension. Ascites is uncommon (10%) in pre-sinusoidal portal hypertension. Ascites may be precipitated when cirrhosis is also present or when serum albumin (and thus oncotic pressure) deceases after high-volume fluid resuscitation for a major gastrointestinal bleed.

• Clinical evaluation and liver tests

• Doppler ultrasonography

Portal vein thrombosis is suspected in patients with the following:

• Manifestations of portal hypertension without cirrhosis

• Mild abnormalities in liver function or enzymes plus risk factors such as neonatal umbilical infection, childhood appendicitis, or a hypercoagulability disorder

Doppler ultrasonography is usually diagnostic, showing diminished or absent portal vein flow and sometimes the thrombus. Difficult cases may require MRI or CT with contrast. Angiography may be required to guide shunt surgery.

In patients with cirrhosis, venous obstruction due to hepatocellular carcinoma should be excluded with contrast‐enhanced imaging studies. In patients without cirrhosis who have thrombosis of the portal venous system without a clear cause, myeloproliferative disorders or other thrombophilic conditions should be excluded; consultation with a hematologist should be considered (1).

• For some acute cases, thrombolysis

• Long-term anticoagulation

• Management of portal hypertension and its complications

In acute cases, thrombolysis is sometimes successful, best reserved for recent occlusion, particularly in hypercoagulable states (1). Anticoagulation does not lyse clots but has some value for long-term prevention in hypercoagulable states despite the risk of variceal bleeding. In neonates and children, treatment is directed at the cause (eg, omphalitis, appendicitis). Otherwise, management is directed at the portal hypertensionportal vein thrombosis (2).