What is the appropriate diagnostic work‑up and management for hepatic stenosis—including hepatic artery, portal vein, hepatic vein, or intra‑hepatic biliary tree—in an adult patient?

Hepatic Stenosis: Diagnostic Work-Up and Management

Initial Diagnostic Approach

For any suspected hepatic stenosis involving the hepatic artery, portal vein, hepatic vein, or biliary tree, begin with Doppler ultrasound as the first-line imaging modality, followed by multiphasic contrast-enhanced CT or MRI to characterize the stenosis and assess for complications. 1

Vascular Stenosis Evaluation

Hepatic Artery Stenosis:

• Doppler ultrasound should assess peak flow velocity (>80 cm/sec suggests stenosis), resistivity index (<0.55 abnormal), and hepatic artery diameter (>6 mm extrahepatic dilatation indicates stenosis) 1
• Multiphasic CT angiography with late arterial, portal venous, and delayed phases provides 84% sensitivity and 95% specificity for hepatic artery involvement 1
• CT findings of stenosis or occlusion are highly suggestive for arterial involvement, while absence of tumor-vessel contact has very high negative predictive value 1
• In post-transplant patients, hepatic artery stenosis occurs in 3-5% of cases, with median diagnosis at 100 days post-transplant 2, 3

Portal Vein Stenosis:

• Doppler ultrasound should measure flow velocity within the portal vein trunk and assess for flow direction abnormalities 1
• CT angiography demonstrates 89% sensitivity and 92% specificity for portal vein involvement 1
• Look for circumferential contact >180°, encasement, occlusion, stenosis, or contour deformity 1

Hepatic Vein Stenosis:

• Doppler ultrasound should assess hepatic vein flow patterns and detect flow abnormalities 1
• Hepatic vein stenosis occurs in 1-6% of post-transplant patients and can cause portal hypertension, renal dysfunction, or lower-extremity edema 2
• MRI with contrast can provide additional anatomical detail when ultrasound findings are equivocal 1

Biliary Stenosis Evaluation

Intrahepatic Biliary Tree Stenosis:

• MRCP with long T2 single-shot sequences provides superior visualization of biliary anatomy and extent of stenosis compared to CT 1
• Assess for upstream and downstream extension of obstruction, variant ductal anatomy, and associated complications 1
• In post-transplant patients, biliary strictures occur in 33% of those with hepatic artery stenosis versus 7.1% without vascular compromise 4

Management Algorithm

For Hepatic Artery Stenosis

Post-Transplant Setting:

• Immediate surgical revision is indicated when stenosis causes liver dysfunction or threatens graft survival 3
• Revision options include: resection with primary reanastomosis (preferred for focal stenosis), aortohepatic iliac artery graft, interposition vein graft, or vein patch angioplasty 3
• Percutaneous transluminal balloon angioplasty can be attempted for focal, non-calcified stenoses, though long-term patency is lower than surgical revision 3
• Post-revision hepatic artery patency is achieved in 78% of cases, with 4-year patient survival of 65% 3

Non-Transplant Setting:

• Evaluate for underlying malignancy (cholangiocarcinoma) as stenosis may represent tumor encasement 1
• If malignant, assess resectability based on extent of vascular involvement and presence of metastases 1

For Portal Vein Stenosis

Budd-Chiari Syndrome or Hepatic Vein Stenosis:

• Immediate anticoagulation with low molecular weight heparin for 5-7 days, transitioning to vitamin K antagonist targeting INR 2-3 1
• Angioplasty with stenting for partial or segmental stenoses (present in 60% of IVC obstruction, 25-30% of hepatic vein obstruction) 1
• TIPS placement for patients non-responsive to medical treatment or not candidates for angioplasty/stenting 1
• Monitor with Doppler ultrasound every 6 months to assess TIPS patency and flow velocities 1

Portal Vein Thrombosis with Stenosis:

• Beta-adrenergic blockade decreases bleeding risk in patients with large varices and improves survival 1
• Endoscopic variceal band ligation for primary or secondary prophylaxis of variceal bleeding 1
• Consider surgical portosystemic shunting using superior mesenteric or splenic veins in selected patients 1

For Biliary Stenosis

Post-Transplant Ischemic Biliary Strictures:

• Biliary strictures develop in 40% of patients with early hepatic artery stenosis (≤90 days) and 26% with late stenosis (>90 days) 4
• ERCP with repeated stenting for symptomatic strictures causing jaundice or cholangitis 1
• Risk of hemobilia from intrabiliary varices during endobiliary procedures—proceed with caution 1
• Liver function test elevation ≥3× upper limit of normal at diagnosis indicates higher likelihood of requiring biliary intervention 4

Malignant Biliary Stenosis:

• Tissue diagnosis via ERCP with brush cytology (40-70% sensitivity) or direct bile aspirate for methylation markers (100% sensitivity, 90% specificity in PSC-related cholangiocarcinoma) 1
• Avoid percutaneous biopsy due to risk of tumor spillage 5

Critical Monitoring and Follow-Up

Post-Intervention Surveillance:

• Doppler ultrasound at 4-6 weeks post-intervention, then every 6 months to assess patency 1
• Measure maximum flow velocity in portal vein and stent, assess flow direction in intrahepatic portal vein branches 1
• Invasive portography with pressure measurement only when ultrasound suggests dysfunction or clinical failure occurs 1

Complications to Monitor:

• Hepatic encephalopathy develops in 15-67% over 2 years after TIPS, with 8% persistent overt encephalopathy 1
• Biliary complications requiring intervention are more likely when liver enzymes are significantly elevated at stenosis diagnosis 4
• Retransplantation may be necessary if graft function deteriorates despite vascular revision 3

Common Pitfalls

• Do not delay anticoagulation in hepatic vein stenosis/Budd-Chiari syndrome—bleeding risk is manageable with proper portal hypertension prophylaxis 1
• Do not perform routine invasive portography for TIPS surveillance—reserve for clinical or ultrasound suspicion of dysfunction 1
• Do not assume biliary strictures are benign in the setting of vascular stenosis—ischemic injury is common and progressive 4
• Do not overlook hepatic artery stenosis as a cause of biliary complications in transplant patients—33% will develop strictures 4