BUDD–CHIARI SYNDROME DIAGNOSIS

Budd–Chiari syndrome (BCS)
Budd–Chiari syndrome is the name given to the symptoms associated with partial or complete occlusion of the hepatic veins.

There are numerous causes of hepatic vein occlusion, of which the main ones are:
● congenital or acquired coagulation disorders, which may affect both the hepatic and portal veins (potentially treatable by liver transplant)
● malignancy: primary or secondary liver tumour may invade the hepatic veins or may travel up the IVC (for example renal carcinoma) to occlude the hepatic vein confluence
● congenital web obstructing the IVC (surgically removable).

Ultrasound appearances of Budd–Chiari syndrome
In the acute stage, the liver may enlarge. As the condition progresses, compensatory hypertrophy of any ‘spared’ segments occurs—usually the caudate lobe, because the venous drainage from here is inferior to the main hepatic veins. The hepatic veins may be difficult or impossible to visualize.

Dilated serpiginous collateral veins may form to direct blood away from the liver and in some cases the portal venous flow reverses to achieve this. The spleen also progressively enlarges and, if the disease is long-standing, the liver becomes cirrhotic, acquiring a coarse texture. Ascites may also be present, particularly if there is complete obstruction involving the IVC. The cause of IVC obstruction may be a web, which can occasionally be identified on ultrasound. If the cause of BCS is a coagulation disorder, the portal venous system may also be affected by thrombosis, causing portal hypertension. Doppler is particularly helpful in diagnosing BCS. The hepatic veins and IVC may be totally or partially occluded; if partial, the waveforms may become flattened, losing their characteristic triphasic pattern. In some cases flow may be reversed in the IVC, hepatic and/or portal veins. Ultrasound may miss partial hepatic vein occlusion, but the use of contrast agents in suspected cases of BCS may improve diagnostic accuracy.

Management of Budd–Chiari syndrome
This depends upon the cause. Both medical and surgical treatments have mixed success. Severe coagulative disorders may have to be transplanted, although there is a significant risk of recurrence. If the cause is an IVC web, this may be surgically removed. In some patients, palliative treatment with percutaneous stent placement in the hepatic veins can relieve the symptoms of ascites and varices. Ultrasound may assist in guiding the placement of stents.