A 34-year-old woman on oral contraceptive pills presents with vague right upper quadrant abdominal pain and worsening abdominal distention for the past 1 month. On examination, she has right upper quadrant tenderness with hepatomegaly. Her liver function panel shows slightly elevated serum aspartate (AST) and alanine aminotransferase (ALT) but normal bilirubin and coagulation profile. A right upper quadrant ultrasound shows hepatic venous occlusion and a moderate amount of ascites. She is started on anticoagulation as well as diuretics to manage her ascites. Her oral contraceptive pills are stopped and a hypercoagulable workup is initiated. A computed tomographic (CT) scan of her abdomen is undertaken to delineate the extent of hepatic venous thrombosis and further liver pathology. She will require close follow-up to monitor her liver dysfunction and potential intervention with percutaneous or surgical procedures in the future. Figures 48-1,48-2, and 48-3 demonstrate typical images of a patient with long-standing hepatic outflow occlusion.

• 
  

  Rare condition that is more common in females than males and has a median age of presentation at 33 years.¹

  
  
• 
  

  The annual incidence of the syndrome is approximately 0.8 per 1 million population.²

  
  
• 
  

  The syndrome can have a variety of presentations including fulminant, acute, subacute, and chronic forms depending on the extent and rapidity of the venous obstruction.³

• 
  

  Most often related to hepatic vein thrombosis, but can also be secondary to inferior vena cava (IVC) obstruction at the level of the hepatic veins, extrinsic compression from tumor, or intrinsic congenital venous membranous webs.

  
  
• 
  

  The syndrome should be distinguished from veno-occlusive disease, which involves obliteration of the microvasculature within the liver parenchyma.

  
  
• 
  

  Underlying hematologic disorders are the most common cause and can be acquired or congenital. Polycythemia vera and paroxysmal nocturnal hemoglobinuria are the two most common hereditary conditions, whereas oral contraception usage and postpartum states are the most common acquired conditions.^1,3

  
  
• 
  

  Numerous other disease states are associated with this condition, including trauma, connective tissue disorders, and intrinsic membranous webs, which are more common in Japan and China.^1,4

  
  
• 
  

  Tumors such as adrenal carcinoma, hepatocellular carcinoma, and retroperitoneal sarcomas can cause extrinsic compression on the hepatic veins and vena cava, leading to liver outflow obstruction.

  
  
• 
  

  Venous outflow obstruction leads to increased liver sinusoidal pressure, which results in centrilobular necrosis. Chronic regeneration can lead to fibrosis and ultimately cirrhosis with resultant liver failure.³

  
  
• 
  

  Liver function can be maintained if sinusoidal pressures can be reduced either by the creation of portosystemic shunt or by collateral development between the portal and system circulation provided the outflow obstruction has developed over a time.

  
  
• 
  

  Most cases are subacute in nature, with symptoms developing over weeks to months. Occasionally the presentation can take on a rapidly fulminant course or a more indolent chronic course, especially in cases of partial venous obstruction.⁵