What is the recommended workup for an incidental thrombus?

Recommended Workup for Incidental Thrombus

Incidental thrombus should be managed in the same manner as symptomatic thrombus, with therapeutic anticoagulation as the primary treatment approach unless contraindicated. 1

Initial Assessment

• Determine the location and extent of the thrombus (segmental, subsegmental, proximal, or multiple vessels) 1
• Assess for symptoms that may have been overlooked or attributed to other causes 1
• Evaluate for underlying risk factors, particularly cancer, which is commonly associated with incidental thrombosis 1
• Check for contraindications to anticoagulation (active bleeding, severe thrombocytopenia, recent surgery) 1

Diagnostic Workup

For Venous Thromboembolism (VTE)

• Complete blood count to assess for thrombocytopenia or other cytopenias 1
• Basic coagulation studies (PT/INR, aPTT) 1
• Renal and hepatic function tests to guide anticoagulant selection 1
• Consider screening for underlying malignancy if not already known:
  • Careful history taking and physical examination 1
  • Basic laboratory tests 1
  • Chest X-ray (if CT pulmonary angiogram was not already performed) 1
  • Note: Extensive cancer screening with comprehensive CT abdomen or PET scans has not been shown to detect more cancers than limited screening in patients with unprovoked VTE 1

For Specific Types of Thrombi

• Pulmonary Embolism (PE):

  • Echocardiography to assess for right ventricular dysfunction in patients with moderate to large PE 1
  • Consider lower extremity compression ultrasound to look for concurrent DVT 1

• Cerebral Venous Thrombosis:

  • MRI of the head with MR venography (MRV) 1
  • Consider contrast-enhanced MRV for increased sensitivity 1

• Splanchnic or Hepatic Vein Thrombosis:

  • Consider testing for hypercoagulable disorders and myeloproliferative neoplasms (including JAK2V617F mutation) 2
  • Flow cytometric assessment for paroxysmal nocturnal hemoglobinuria 2

Management Recommendations

For Incidental Pulmonary Embolism

• Treat incidental PE with therapeutic anticoagulation if it involves segmental or more proximal branches, multiple subsegmental vessels, or a single subsegmental vessel with proven DVT 1
• For isolated subsegmental PE, treatment should be decided on a case-by-case basis, considering potential benefits and risks of anticoagulation 1

For Incidental DVT

• Treat with therapeutic anticoagulation similar to symptomatic DVT 1
• Duration of anticoagulation:
  • For cancer-associated thrombosis: minimum 6 months, consider indefinite treatment until cancer is cured 1
  • For non-cancer related: typically 3 months 1

For Incidental Splanchnic or Hepatic Vein Thrombosis

• For symptomatic splanchnic vein thrombosis: anticoagulation is recommended 1
• For incidentally detected splanchnic or hepatic vein thrombosis: anticoagulation may be withheld, especially if radiologic evidence indicates chronic thrombus 1
• Consider repeated imaging to detect thrombus progression if anticoagulation is not given 1

Anticoagulation Options

• For cancer-associated thrombosis:

  • Low molecular weight heparin (LMWH) is preferred for the first 6 months 1
  • Edoxaban or rivaroxaban may be considered as alternatives to LMWH in patients without gastrointestinal cancer 1
  • Extended anticoagulation beyond 6 months should be considered for an indefinite period or until cancer is cured 1

• For non-cancer associated thrombosis:

  • Direct oral anticoagulants (DOACs) or vitamin K antagonists are appropriate options 1

Follow-up Recommendations

• Serial imaging to assess for thrombus resolution:

  • For venous sinus thrombosis: follow-up at 3-6 months to assess for recanalization 1
  • For PE/DVT: consider follow-up imaging if symptoms persist or worsen 1

• Monitor for bleeding complications, which are common with anticoagulation in patients with cancer (12.4% cumulative incidence of major bleeding at 1 year) 1

Special Considerations

• Thrombocytopenia: Requires dose adjustment or alternative approaches based on platelet count 1
• Intracranial malignancies: Anticoagulation can be used with caution; rates of symptomatic intracranial hemorrhage range from 0-7% 1
• Catheter-related thrombosis: Consider keeping functional catheters in place if there is ongoing need, while continuing anticoagulation 1