What is the approach to diagnosing Budd-Chiari syndrome?

Diagnosis of Budd-Chiari Syndrome

Doppler ultrasound performed by an experienced operator is the first-line diagnostic test for Budd-Chiari syndrome, with diagnostic sensitivity exceeding 75%, and should be followed by MRI or CT for confirmation when the diagnosis is suspected. 1, 2

Clinical Suspicion

Consider BCS in any patient presenting with the triad of ascites, hepatomegaly, and abdominal pain, particularly when combined with known hypercoagulable states. 1

• Ascites is present in 83% of patients at diagnosis 3
• Hepatomegaly occurs in 67% of patients 3
• Abdominal pain is present in 90% of acute presentations 4
• The clinical presentation ranges from asymptomatic to fulminant hepatic failure 3

Maintain high clinical suspicion even with normal or only mildly abnormal liver function tests, as these are often nonspecific. 4

Diagnostic Algorithm

Step 1: Doppler Ultrasound (First-Line)

Perform Doppler ultrasound as the initial imaging study when BCS is suspected. 1, 2

Key diagnostic features on Doppler ultrasound include:

• Absence of visualization or tortuosity of hepatic veins 2
• Intrahepatic or subcapsular hepatic venous collaterals (present in >80% of cases) 2
• Caudate lobe enlargement 2
• Demonstration of obstruction or thrombosis of at least one major hepatic vein 4

If Doppler ultrasound is negative but clinical suspicion remains high, reevaluate the patient with an expert radiologist experienced in hepatic vascular imaging. 1

Step 2: MRI or CT for Confirmation

Use MRI or CT to confirm the diagnosis when Doppler ultrasound suggests BCS. 1

• MRI with hepato-specific contrast agents is particularly useful for detecting hypervascular liver nodules and characterizing solid endoluminal material 2
• MRI is more accurate than direct venacavography for characterizing solid material in the IVC 1, 2
• CT has significant limitations with false positive and indeterminate results in approximately 50% of cases 1, 2
• CT also carries risks of radiation exposure and potential renal toxicity from iodinated contrast 2

MRI is preferred over CT for diagnostic confirmation due to superior accuracy and lack of radiation exposure. 2

Step 3: Direct Venography (When Needed)

Perform direct X-ray hepatic venography only in difficult cases where non-invasive imaging is inconclusive or when precise delineation of obstructive lesions is needed before planning interventional treatment. 1, 2

• Venography is essential for treatment planning before angioplasty, stenting, or TIPS 1, 2
• Diagnostic pitfalls include failure to cannulate hepatic vein ostia and distorted appearance of hepatic veins 1
• Anticoagulation increases the risk of hematoma at the puncture site 1
• Percutaneous venous puncture may delay initiation of thrombolytic therapy 1

Step 4: Liver Biopsy (Selected Cases)

Consider liver biopsy only when imaging studies (Doppler ultrasound, MRI, CT) fail to establish a diagnosis despite high clinical suspicion. 1

Histologic features supporting BCS diagnosis:

• Centrilobular congestion, liver cell loss, and fibrosis 1
• Sinusoidal dilatation with centrilobular predominance 1
• Absence of congestion argues strongly against hepatic vein thrombosis 1

Perform liver biopsy first when large hepatic veins and IVC appear clearly patent on imaging, as this suggests small vessel disease. 1

Use venography as the first procedure when hepatic vein appearance is abnormal but not definitively diagnostic. 1

Etiologic Workup

Once BCS is diagnosed, immediately initiate comprehensive thrombophilia screening and evaluation for myeloproliferative neoplasms. 3

Thrombophilia Screening:

• Factor V Leiden mutation 5, 3
• Prothrombin G20210A gene variant 5, 3
• Protein C, protein S, and antithrombin levels 3
• Antiphospholipid antibodies 3

Myeloproliferative Neoplasm Evaluation:

• JAK2V617F mutation testing (positive in approximately 45% of BCS patients) 1, 3
• Calreticulin mutation screening 3
• Bone marrow histology 3

At least one thrombotic risk factor is identified in 84% of BCS patients, with myeloproliferative disorders being the most common (49% of cases). 6

Common Diagnostic Pitfalls

Avoid misdiagnosing BCS as cirrhosis, which occurred in 80% of patients with membranous BCS in one series. 7

Do not rely solely on CT scan, as it failed to detect membranous obstruction in multiple case series despite being considered a "gold standard." 7

Recognize that liver cirrhosis may be a consequence of chronic BCS rather than the primary diagnosis. 7

Be aware that significant sample variation and lack of independent prognostic value make liver biopsy useless for prognostication and therapeutic decision-making. 1

Monitoring After Diagnosis

Perform Doppler ultrasound every 6 months after diagnosis to monitor for disease progression and assess response to treatment. 2

After TIPS placement, perform early Doppler ultrasound followed by surveillance every 6 months to detect thrombosis or shunt dysfunction. 1, 2