What is the recommended management and surveillance for a patient with an aortic mural thrombus?

Management and Surveillance of Aortic Mural Thrombus

For patients with aortic mural thrombus, immediate anticoagulation with unfractionated heparin or low molecular weight heparin should be initiated urgently, followed by open surgical thrombectomy or endovascular stent graft coverage when feasible, as anticoagulation alone carries a 25-50% embolic recurrence rate and 35% thrombus persistence. 1, 2

Immediate Diagnostic Workup

Multimodality imaging is essential to confirm diagnosis and guide treatment:

• CT angiography (CTA) is the primary diagnostic modality to identify thrombus location, size, mobility, and underlying aortic pathology 3, 1
• Perform cardiac evaluation with Holter-ECG and echocardiography to exclude cardiac sources of embolism 1
• Assess for hypercoagulable states including protein C/S deficiency, antiphospholipid antibodies, and malignancy, as these are frequently present in non-atherosclerotic aortic mural thrombus 4, 5

Initial Medical Management

Start anticoagulation immediately upon diagnosis:

• Initiate unfractionated heparin or low molecular weight heparin without delay to prevent thrombus propagation and further embolization 1, 5
• Transition to warfarin with target INR 2.5-3.5 for long-term management 1
• Continue anticoagulation for minimum 6 months after imaging-confirmed thrombus resolution 1
• Extend anticoagulation indefinitely if persistent aortic wall abnormalities remain or underlying hypercoagulable state cannot be corrected 1

Critical caveat: Anticoagulation alone as definitive therapy is associated with poor outcomes—25-50% embolic recurrence, 35% thrombus persistence, and need for secondary surgery in 31% of cases 2, 6

Definitive Treatment Algorithm

Treatment selection depends on thrombus location and patient characteristics:

For Thoracic Aortic Mural Thrombus (Ascending Aorta/Arch):

• Endovascular stent graft coverage is preferred when anatomy is suitable, with lower recurrence and re-embolization rates compared to anticoagulation alone 2, 5
• Bare metal stents can be used as alternative if stent grafts are not feasible 5
• Open surgical thrombectomy in hybrid operating room with completion angiography if endovascular approach not possible 1, 5

For Suprarenal/Perivisceral Aortic Thrombus:

• Open trapdoor aortic thrombectomy is recommended when thrombus is adjacent to visceral vessels 5
• Endovascular approaches risk covering visceral ostia 5

For Infrarenal Aortic Thrombus:

• Aortobifemoral embolectomy or surgical thrombectomy for acute presentations 5
• Aortic stenting when anatomy suitable 5

Important note: Polycythemia vera and other severe hypercoagulable states may be prohibitive risks for endovascular exclusion—proceed with extreme caution 7

High-Risk Features Predicting Recurrence

Logistic regression identifies these predictors requiring aggressive intervention:

• Thrombus in ascending aorta (OR 12.7) or arch (OR 18.3) 6
• Mild atherosclerosis of aortic wall (OR 2.5) 6
• Stroke as presenting symptom (OR 11.8) 6
• Mobile thrombus on imaging 2, 6

Patients with these features should undergo definitive surgical/endovascular treatment rather than anticoagulation alone 6

Surveillance Protocol

Post-treatment imaging surveillance:

• Repeat CTA at 1 month, 3 months, 6 months, then annually to confirm thrombus resolution 1
• Monitor INR weekly during warfarin initiation, then monthly once stable, maintaining time in therapeutic range >70% 1
• Continue surveillance indefinitely if aortic wall abnormalities persist 1

Management of Embolic Complications

For acute limb ischemia from aortic embolization:

• Assess limb viability immediately using Doppler signals 1
• Perform urgent revascularization for salvageable limbs 1
• Follow with definitive treatment of aortic source 1

Critical Pitfalls to Avoid

• Never delay anticoagulation once diagnosis confirmed—this significantly increases embolic stroke and limb loss risk 1
• Do not stop anticoagulation based on symptom improvement alone without imaging confirmation of complete thrombus resolution 1
• Do not rely on anticoagulation as sole definitive therapy in young patients or those with high-risk features, as surgical outcomes are superior 6
• Avoid endovascular exclusion in patients with severe hypercoagulable states like polycythemia vera without careful risk assessment 7
• Major limb amputation rates are 9% with anticoagulation alone versus 2% with surgery 6

Comparative Outcomes Data

Surgery versus anticoagulation as primary treatment:

• Thrombus persistence/recurrence: 5.7% surgery vs 26.4% anticoagulation 6
• Recurrent embolization: 9.1% surgery vs 25.7% anticoagulation 6
• Mortality: 5.7% surgery vs 6.2% anticoagulation (not significantly different) 6
• Complications: 17% surgery vs 27% anticoagulation 6

These data support surgical/endovascular management as primary treatment when feasible, particularly in good operative candidates with high-risk features 6