Portal vein thrombosis (PVT) refers to complete or partial closure of the portal vein due to a thrombus. Underlying causes include cirrhosis and malignancy. Acute PVT may present with abdominal pain and ascites, whereas chronic PVT is often asymptomatic. PVT is typically diagnosed with imaging demonstrating thrombus in the portal vein. Treatment depends on the acuity and whether there is underlying cirrhosis and typically consists of anticoagulation or thrombolysis; TIPS may be indicated in select cases.
- Cirrhosis or chronic liver disease
- Local complications of intraabdominal malignancy (e.g., HCC, pancreatic carcinoma) or inflammation (e.g., liver abscess, pancreatitis, cholangitis)
- Thrombophilia (e.g., antiphospholipid syndrome, factor V Leiden) or general risk factors of phlebothrombosis
- Myeloproliferative disorder
- Following TIPS procedure
- Chronic mesenteric venous thrombosis
- Possibly caused by an imbalance of coagulation factors in patients with impaired hepatic synthetic function
- The closure of portal vein flow → ↓ liver blood flow → vasodilation of the hepatic artery and development of collateral hepatic veins in an attempt to maintain liver perfusion
- Thrombotic closure of the splenic and superior mesenteric veins may extend to the portal vein → portal hypertension
Depend on the extent of thrombosis and the speed of manifestation
- Acute PVT
- Chronic PVT
- Duplex ultrasound: decreased flow velocity or no flow in the portal vein
- Other abdominal ultrasound findings 
- CT or MRI abdomen (with contrast): to simultaneously investigate other abdominal organs and for patients with suspected cancer 
- Other studies
- All patients: Management is guided by the presumed time of onset of thrombosis and the degree of suspicion of intestinal ischemia.
- Patients with cirrhosis: Individualize treatment based on the degree of occlusion and other symptoms.
- Patients without cirrhosis with recent PVT: Consider anticoagulation.
Management of PVT (e.g., anticoagulation) is determined on a case-by-case basis and specialists should be involved early.
- Traditional anticoagulants 
- Direct oral anticoagulants: e.g., apixaban