What is the recommended treatment for a patient with an infrarenal mural thrombus and a history of aneurysm?

Treatment of Infrarenal Mural Thrombus with History of Aneurysm

For patients with infrarenal mural thrombus and a history of aneurysm, antiplatelet therapy with aspirin is recommended as the primary treatment, with consideration for surgical or endovascular intervention if the aneurysm meets size criteria or is symptomatic. 1, 2

Assessment and Monitoring

• Patients with infrarenal mural thrombus and history of aneurysm should undergo comprehensive imaging with ultrasound or CT scans to determine the current size of the aneurysm, extent of thrombus, and involvement of branch vessels 1
• For infrarenal aneurysms measuring 4.0 to 5.4 cm in diameter, monitoring by ultrasound or CT scans should be performed every 6 to 12 months to detect expansion 1
• For aneurysms smaller than 4.0 cm in diameter, monitoring by ultrasound examination every 2 to 3 years is reasonable 1
• Patients with femoral or popliteal aneurysms should undergo imaging to exclude contralateral femoral or popliteal aneurysms and abdominal aortic aneurysm 1

Medical Management

• Aspirin therapy is recommended for patients with infrarenal mural thrombus as it is associated with decreased thrombus sac volume and may help prevent thromboembolic complications 2
• Beta-adrenergic blocking agents may be considered to reduce the rate of aneurysm expansion in patients with aortic aneurysms 1
• Smoking cessation interventions, including behavior modification, nicotine replacement, or bupropion, should be offered to patients with aneurysms or a family history of aneurysms 1
• Blood pressure control is essential in managing patients with mural thrombus and history of aneurysm to reduce the risk of expansion and rupture 1

Indications for Intervention

• Repair is indicated for patients with infrarenal or juxtarenal AAAs measuring 5.5 cm or larger to eliminate the risk of rupture 1
• Repair can be beneficial in patients with infrarenal or juxtarenal AAAs 5.0 to 5.4 cm in diameter 1
• In patients with symptomatic aortic aneurysms, repair is indicated regardless of diameter 1
• Intervention is not recommended for asymptomatic infrarenal or juxtarenal AAAs if they measure less than 5.0 cm in diameter in men or less than 4.5 cm in diameter in women 1

Intervention Options

• Open or endovascular repair of infrarenal AAAs and/or common iliac aneurysms is indicated in patients who are good surgical candidates 1
• For patients with mural thrombus in the setting of aneurysm, special attention must be paid to the risk of atheromatous embolization during endovascular procedures, particularly in cases with friable thrombus 3
• Open aneurysm repair is reasonable to perform in patients who are good surgical candidates but who cannot comply with the periodic long-term surveillance required after endovascular repair 1
• Endovascular repair of infrarenal aortic aneurysms in patients who are at high surgical or anesthetic risk due to coexisting severe cardiac, pulmonary, and/or renal disease is of uncertain effectiveness 1

Post-Intervention Surveillance

• After endovascular repair, periodic long-term surveillance imaging should be performed to monitor for endoleak, document shrinkage or stability of the excluded aneurysm sac, and determine the need for further intervention 1
• Annual duplex ultrasound surveillance is recommended to monitor for development of endoleaks, changes in aneurysm sac size, stent graft patency, and stent migration or kinking 4
• Cross-sectional imaging with CT or MRI every 5 years is recommended to assess stent integrity, evaluate for subtle endoleaks, and check for stent migration or fracture 4
• Immediate additional cross-sectional imaging with CT or MRI is indicated if endoleak, aneurysm sac enlargement, stent migration, kinking of the stent graft, or decreased flow in the stent graft is detected on surveillance ultrasound 4

Special Considerations

• The morphology of mural thrombi deposition can vary, with anterior wall deposition being most common (53% of cases), followed by concentric deposition (23%) and posterior wall deposition (11%) 5
• Patients with a "shaggy aorta" (friable mural thrombus in the aorta) may be at higher risk for diffuse atheromatous embolization during endovascular procedures, which can lead to catastrophic complications 3
• The presence of mural thrombus covering the ostium of branch vessels (such as the inferior mesenteric artery) requires special attention as it may lead to ischemic complications 6