What is the recommended management for an asymptomatic patient without connective‑tissue disease who has a 1.9 cm saccular descending thoracic aortic aneurysm with an eccentric mural thrombus?

Management of 1.9 cm Saccular Descending Thoracic Aortic Aneurysm with Eccentric Mural Thrombus

For an asymptomatic patient without connective tissue disease who has a 1.9 cm saccular descending thoracic aortic aneurysm with eccentric mural thrombus, initiate immediate therapeutic anticoagulation and consider elective endovascular repair (TEVAR) given the high-risk features of saccular morphology and mural thrombus presence. 1, 2

Primary Treatment: Immediate Anticoagulation

The presence of mural thrombus mandates immediate anticoagulation to prevent catastrophic embolic events, regardless of aneurysm size. 2, 3

• Start unfractionated heparin or low molecular weight heparin as bridge therapy while initiating warfarin, targeting INR 2.0-3.0 2, 3
• Monitor INR weekly during initiation and monthly once stable, maintaining time in therapeutic range >70% 2, 3
• Continue anticoagulation for a minimum of 6 months, with duration guided by repeated imaging to confirm thrombus resolution 2, 3
• Do not delay anticoagulation once diagnosis is confirmed, as this is the single most important intervention to prevent embolic stroke and limb loss 2, 3

Consideration for Endovascular Repair

Saccular aneurysms with eccentric mural thrombus represent localized lesions that are highly suitable for endovascular treatment, even below traditional size thresholds. 1

Indications Favoring TEVAR in This Case:

• Saccular morphology indicates a focal intimal defect, which represents a target lesion easily excluded from circulation by endograft 1
• Eccentric mural thrombus suggests poor wall adherence and increased embolic risk, meeting high-risk criteria for intervention 2
• These lesions are treated based on maximum diameter and clinical features rather than strict size cutoffs for fusiform aneurysms 1
• TEVAR demonstrates 93.1% complete thrombus exclusion with minimal recurrence rates 2

Technical Considerations:

• Ensure adequate distance from critical branch arteries (intercostals, left subclavian) for proximal and distal landing zones 1
• Confirm external aortic diameter measurements on CT angiography, as mural thrombus makes lumen size underestimate true vessel diameter 1
• Plan for coverage of the entire saccular segment plus safety margin to address adjacent atheromatous wall 1

Alternative: Medical Management with Surveillance

If TEVAR is deferred due to patient preference or anatomic constraints, aggressive medical management with intensive surveillance is required. 1

Medical Therapy:

• Beta-blocker therapy to reduce aortic wall stress 1
• Aggressive blood pressure control with target systolic BP <120 mmHg 1
• Smoking cessation if applicable 4
• Continue therapeutic anticoagulation indefinitely given persistent thrombus 2, 3

Surveillance Protocol:

• Perform serial CT angiography at 2 weeks, 1 month, 3 months, and 6 months to assess thrombus resolution and aneurysm stability 2, 3
• Do not discontinue anticoagulation based solely on symptom improvement without imaging confirmation of complete thrombus resolution 2, 3
• Extend anticoagulation indefinitely if persistent aortic wall abnormalities or thrombus remain 2, 3

Indications for Urgent Intervention

Proceed immediately to TEVAR or open repair if any of the following develop: 1, 2

• New symptoms (chest pain, back pain, embolic phenomena) 1
• Recurrent embolism despite therapeutic anticoagulation 2
• Aneurysm expansion on surveillance imaging 1
• Persistent or enlarging thrombus after 3-6 months of anticoagulation 2

Management of Embolic Complications

If acute limb ischemia or visceral embolization occurs: 2, 3

• Assess limb viability immediately using Doppler signals 2, 3
• Perform urgent revascularization (thrombectomy or bypass) for salvageable limbs 2, 3
• Follow with definitive treatment of aortic source with TEVAR to prevent recurrent embolization 2
• Continue therapeutic anticoagulation throughout to prevent thrombus propagation 2, 3

Critical Pitfalls to Avoid

• Do not apply standard fusiform aneurysm size thresholds (5.0-5.5 cm) to saccular aneurysms, as these focal lesions carry higher rupture risk at smaller diameters and warrant earlier intervention 1
• Do not confuse mural thrombus with intramural hematoma (IMH)—IMH represents hemorrhage within the aortic wall rather than luminal thrombus and follows different management algorithms 2, 3
• Do not rely on lumen diameter alone for sizing, as eccentric mural thrombus causes significant underestimation of true external aortic diameter 1
• Do not defer anticoagulation pending surgical decision, as embolic complications can occur at any time 2, 3

Contraindications to Consider

This patient explicitly does not have connective tissue disease, which is critical because: 5, 6, 7

• TEVAR in connective tissue disorders (Marfan, Loeys-Dietz, Ehlers-Danlos) is associated with high rates of early and mid-term complications due to fragile aortic tissue 5, 6, 7
• Open repair remains the gold standard for patients with connective tissue disorders 5, 6
• The absence of connective tissue disease makes this patient an ideal candidate for endovascular therapy 1