Vascular Diseases of the Liver

Vascular disease of the liver can result from a number of conditions that alter the normal flow of blood within the hepatic vascular system. These diseases are usually categorized based on the location of the lesion or lesions responsible for altering the flow, in reference to the sinusoids. Thus vascular diseases of the liver can be presinusoidal, such as portal vein thrombosis and shistosomiasis, intrasinusoidal such as most cases of liver cirrhosis, or post sinusoidal such as Budd-Chiari syndrome (BCS) or Sinusoidal Obstruction Syndrome (Veno occlusive disease). Budd-Chiari Syndrome is a heterogeneous disorder characterized by partial or full occlusion at the level of the hepatic veins or the suprahepatic portion of the inferior vena cava (IVC). It typically presents with painful hepatomegaly, ascites and abnormal liver tests. Most cases occur in the setting of myeloproliferative disorders (MPD) or hypercoaguable states. Diagnosis is usually established non-invasively with Doppler ultrasound, CT scan, or MR angiography. Venography and liver biopsy are rarely needed. Treatment is determined by the disease severity, underlying etiology and duration of the disease. Treatment options include medical (supportive care, diuretics, anticoagulation, thrombolysis), radiological intervention with TIPS, or rarely surgical (surgical shunts or liver transplant). Portal vein thrombosis (PVT) refers to thrombosis that involves the trunk of the portal vein and represents the classical form of presinusoidal portal hypertension. It occurs in both children and adults and is the leading cause of extra-hepatic portal hypertension in non-cirrhotic patients in western countries. Clinical presentation is usually subtle and most patients will present with manifestations of portal hypertension: abdominal pain, abdominal distension due to ascites, variceal bleeding and splenomegaly. Liver cirrhosis is the most common acquired cause of PVT in adults. Other causes include neoplastic disorders, infections and hypercoaguable disorders. Ultrasonography is the first line diagnostic modality with high sensitivity and specificity. Contrast CT scan and magnetic resonance imaging usually help to confirm the diagnosis and determine the extent of the thrombus. Treatment is directed at management of portal hypertension complications; the role of anticoagulation remains controversial. This chapter will address both BCS and PVT. Sinusoidal obstruction syndrome will be discussed in a separate chapter dealing with complications of stem cell transplantation.