Aortic Aneurysm Management

Diagnosis and Surveillance

• For aortic aneurysms, close imaging surveillance every 6 months with CT or MRI is recommended for aneurysms ≥4.9 cm, with surgical intervention indicated if the aneurysm reaches ≥5.5 cm or demonstrates rapid growth (≥0.3 cm/year for two consecutive years or ≥0.5 cm in one year), as per the American College of Cardiology 1
• Consider earlier intervention if the patient has a low surgical risk, the procedure is performed by experienced surgeons in a Multidisciplinary Aortic Team, and the patient has a bicuspid aortic valve, family history of dissection, or significant aortic regurgitation, with a lower threshold of ≥5.0 cm 1
• Immediate intervention is recommended regardless of size if there is development of symptoms attributable to the aneurysm or a growth rate ≥0.3 cm/year for two consecutive years or ≥0.5 cm in one year 1
• The European Society of Cardiology considers an aortic diameter ≥4.0 cm to be generally enlarged for most segments of the aorta in adults 2, 1
• Normal aortic dimensions vary by location, with the following measurements:
• The recommended surveillance frequency is as follows:

• Approaching intervention threshold warrants consideration of imaging every 3-6 months, and stable aneurysms over years may allow for extended intervals, especially for non-genetic aneurysms <4.5 cm 3, 4

Treatment

• For aneurysms involving both ascending aorta and proximal arch, partial arch replacement with ascending aorta repair using right subclavian/axillary artery inflow and hypothermic circulatory arrest is recommended 3
• For aneurysms of the entire arch, complete arch replacement, potentially with the elephant trunk procedure if the aneurysm extends to the descending thoracic aorta, is recommended 3
• Surgical intervention is recommended for isolated degenerative/atherosclerotic aneurysms in low-risk patients when the diameter reaches ≥5.5 cm, and at ≥4.5 cm when concurrent valve surgery is planned or in patients with specific conditions such as bicuspid aortic valve disease 3, 4, 1
• Endovascular repair is preferred for descending thoracic aneurysms when anatomy is suitable, with lower perioperative morbidity and mortality compared to open repair, although it is not FDA-approved for aortic arch aneurysms 3, 4
• Hybrid procedures, including debranching of supra-aortic vessels and TEVAR, are reasonable for aneurysms involving the aortic arch and proximal descending thoracic aorta 3
• Thoracic endovascular aortic repair (TEVAR) is recommended over open repair when anatomy is suitable 4

Measurement and Assessment

• Avoid using absolute diameter thresholds without considering patient-specific factors such as body size, sex, and underlying etiology 1
• Consider using indexed measurements, such as aortic size index (ASI) ≥3.08 cm/m², aortic height index (AHI) ≥3.21 cm/m, or cross-sectional aortic area/height ratio ≥10 cm²/m, for patients with significant height variations 1
• Ensure consistent measurement technique and imaging modality during follow-up to accurately assess growth rate 1
• The American Heart Association notes that mild dilation (4.0-4.4 cm) requires regular monitoring, while moderate dilation (4.5-5.4 cm) has a higher risk of complications, especially with risk factors, and severe dilation (≥5.5 cm) has a significantly increased risk of dissection or rupture 1

Patient Management

• Patient-specific factors that increase risk include family history of aortic dissection, genetic disorders, bicuspid aortic valve, hypertension, smoking history, and pregnancy plans, as outlined by the European Society of Cardiology 1, 4
• Lifestyle modifications include smoking cessation, regular moderate exercise, avoiding isometric exercises and activities causing sudden blood pressure increases, and avoiding contact sports if the aortic diameter is >40 mm, as advised by the American Heart Association 5, 4
• Blood pressure control with a target <135/80 mmHg is recommended, using beta-blockers as first-line medications, especially for Marfan syndrome, and alternative options such as ARBs or ACE inhibitors, as per the American College of Cardiology 6, 1
• Women have a four-fold higher rupture risk compared to men with similarly sized aneurysms, and specialized management and pre-conception counseling are required for women with aortic aneurysms, especially those with genetic disorders, as recommended by the European Society of Cardiology 4, 6