What is the recommended monitoring and management approach for patients with an aortic aneurysm (AA)?

Aortic Aneurysm Monitoring and Management Recommendations

Regular surveillance with specific imaging modalities and intervals based on aneurysm size and location is recommended for all aortic aneurysms, with intervention indicated at diameter thresholds of ≥55 mm for men and ≥50 mm for women with abdominal aortic aneurysms (AAA), or ≥55 mm for thoracic aortic aneurysms (TAA). 1

Initial Evaluation

• When an aortic aneurysm is identified at any location, assessment of the entire aorta is recommended at baseline and during follow-up 1
• For thoracic aortic aneurysms (TAA), assessment of the aortic valve (especially for bicuspid aortic valve) is recommended 1
• In thoracic aortic dilatation, transthoracic echocardiography (TTE) is recommended at diagnosis to assess aortic valve anatomy and function, aortic root, and ascending aorta diameters 1
• Cardiovascular computed tomography (CCT) or cardiovascular magnetic resonance (CMR) is recommended to confirm TTE measurements, rule out aortic asymmetry, and determine baseline diameters for follow-up in thoracic aortic dilatation 1

Surveillance Protocols

Abdominal Aortic Aneurysm (AAA) Surveillance

• Duplex ultrasound (DUS) is the recommended primary modality for AAA surveillance 1
• Surveillance intervals should follow this schedule:
  • AAA 25-29 mm: Every 4 years 1
  • AAA 30-39 mm: Every 3 years 1
  • AAA 40-44 mm in women or 40-49 mm in men: Annually 1
  • AAA 45-50 mm in women or 50-55 mm in men: Every 6 months 1
• CCT or CMR is recommended if DUS does not allow adequate measurement of AAA diameter 1
• Consider shorter intervals for aneurysms with rapid growth (≥10 mm per year or ≥5 mm per 6 months) 1

Thoracic Aortic Aneurysm (TAA) Surveillance

• For aneurysms of the distal ascending aorta, aortic arch, descending thoracic aorta (DTA), or thoracoabdominal aortic aneurysms (TAAA), CMR or CCT is recommended for surveillance 1
• TTE is not recommended for surveillance of aneurysms in the distal ascending aorta, aortic arch, or DTA 1
• After open repair of TAA, early CCT is recommended within 1 month, then yearly CCT follow-up for the first 2 post-operative years, and every 5 years thereafter if findings are stable 1

Intervention Thresholds

• Abdominal Aortic Aneurysm (AAA):

  • Elective repair is recommended if AAA diameter is ≥55 mm in men or ≥50 mm in women 1
  • Consider repair for rapidly growing aneurysms (≥10 mm per year or ≥5 mm per 6 months) 1
  • In patients with limited life expectancy (<2 years), elective AAA repair is not recommended 1

• Thoracic Aortic Aneurysm (TAA):

  • For aortic root or ascending aorta with tricuspid aortic valve: Surgery when maximum diameter ≥55 mm 1
  • For unruptured descending thoracic aortic aneurysm (without heritable thoracic aortic disease): Elective repair when diameter ≥55 mm 1
  • For unruptured degenerative thoracoabdominal aortic aneurysm: Elective repair when diameter ≥60 mm 1

Medical Management

• Optimal implementation of cardiovascular risk management is recommended for all patients with aortic aneurysms to reduce major adverse cardiovascular events 1
• Key medical interventions include:
  • Blood pressure control 2
  • Smoking cessation 2, 3
  • Statin therapy (has been shown to reduce odds of symptomatic presentation) 4
  • Beta-blockers may reduce risk of symptomatic presentation 4
• Fluoroquinolones should generally be avoided in patients with aortic aneurysms but may be considered if there is a compelling clinical indication and no reasonable alternative 1

Post-Intervention Monitoring

• After endovascular repair (TEVAR/EVAR), 30-day imaging with CCT plus DUS/contrast-enhanced ultrasound is recommended to assess intervention success 1
• After TEVAR, follow-up imaging is recommended at 1 and 12 months post-operatively, then yearly until the fifth post-operative year 1
• Re-intervention is recommended for patients with type I or type III endoleaks after TEVAR/EVAR 1

Special Considerations

• Women have similar aneurysm growth rates to men but a four-fold higher rupture risk at the same diameter 1
• The diameter-to-height index (DHI) may be a better predictor of symptomatic presentation than absolute diameter alone 4
• Saccular aneurysms may have higher rupture risk at smaller diameters than fusiform aneurysms 1
• In centers with operative mortality rates >2%, surgical intervention is not indicated for asymptomatic AAAs <4.5 cm 3

Pitfalls to Avoid

• Do not use TTE for surveillance of aneurysms in the distal ascending aorta, aortic arch, or DTA as visualization is inadequate 1
• Avoid routine evaluation with coronary angiography and systematic revascularization in patients with chronic coronary syndromes prior to AAA repair 1
• Don't neglect to assess the entire aorta when an aneurysm is found at any location, as multiple aneurysms may be present 1
• Remember that women have higher rupture risk at smaller diameters than men, requiring earlier intervention 1