What is the management of portal vein thrombosis?

Management of Portal Vein Thrombosis

Anticoagulation should be initiated immediately in patients with recent (<6 months) portal vein thrombosis (PVT) that is >50% occlusive or involves the main portal vein or mesenteric vessels, while observation with serial imaging is appropriate for patients with <50% occlusion or intrahepatic branch involvement. 1, 2

Classification and Initial Assessment

Portal vein thrombosis should be classified based on:

• Timing: Recent (<6 months) vs. chronic (≥6 months)
• Extent: <50% vs. >50% occlusion
• Location: Main portal vein, intrahepatic branches, mesenteric vessels
• Presence of complications: Intestinal ischemia, cavernous transformation

Diagnostic Approach

• First-line: Doppler ultrasound
• Confirmation: Contrast-enhanced CT scan showing filling defects, mesenteric venous engorgement 2

Management Algorithm

1. Recent PVT (<6 months)

A. <50% occlusion or isolated intrahepatic branches:

• Observation with repeat imaging every 3 months until clot regression
• No immediate anticoagulation needed 1

B. >50% occlusion or main portal/mesenteric vessel involvement:

• Immediate anticoagulation is indicated
• Higher benefit in:
  • Transplant candidates
  • Multiple vascular bed involvement
  • Thrombus progression
  • Inherited thrombophilia 1, 2

2. Chronic PVT (≥6 months)

A. Complete occlusion with cavernous transformation:

• Anticoagulation not recommended
• Manage complications of portal hypertension 1

B. Partial occlusion without cavernoma:

• Lower chance of recanalization
• Individualized decision based on risk factors and symptoms 1

3. PVT with Intestinal Ischemia (Medical Emergency)

• Immediate inpatient care
• Urgent anticoagulation
• Consider interventional approaches if no clinical improvement 2

Anticoagulation Options

All of the following are reasonable options, with selection based on Child-Turcotte-Pugh (CTP) class and patient preference:

1. Low molecular weight heparin (LMWH)

   • Consider monitoring anti-Xa activity in overweight patients or renal dysfunction
   • Target: 0.5-0.8 IU/ml 2

2. Vitamin K antagonists (VKAs)

   • Target INR: 2-3 2

3. Direct oral anticoagulants (DOACs)

   • Suitable for CTP class A and B cirrhosis
   • More convenient (no INR monitoring)
   • Not recommended in CTP class C cirrhosis 1, 2

Monitoring and Duration

• Imaging: Cross-sectional imaging every 3 months to assess response 1
• Duration: Minimum 6 months; continue until:
  • Complete clot resolution in non-transplant candidates
  • Until transplantation in transplant candidates
  • Lifelong in permanent hypercoagulable states 1, 2
• Continuing anticoagulation beyond 6 months without recanalization is unlikely to provide additional benefit 2

Important Considerations

Variceal Screening

• Endoscopic variceal screening is warranted in cirrhotic patients with PVT
• Do not delay anticoagulation for variceal screening as this decreases recanalization rates 1
• Non-selective beta-blockers are recommended for high-risk varices 2

Interventional Approaches

• Transjugular intrahepatic portosystemic shunting (TIPS) may be considered for:
  • Patients with additional indications (refractory ascites, variceal bleeding)
  • Transplant candidates to facilitate technical feasibility 1

Contraindications to Anticoagulation

• High bleeding risk, especially with esophageal varices
• Severe thrombocytopenia (case-by-case decision for platelet count <50 × 10^9/L) 2

Expected Outcomes

• Recanalization rates with anticoagulation: 38-39% for portal vein, 54-80% for splenic vein, 61-73% for superior mesenteric vein 2
• Anticoagulation improves survival (HR: 0.59; 95% CI: 0.49-0.70) 2
• Early initiation (within 2 weeks) improves recanalization rates 1