What is the management of Abdominal Aortic Aneurysm (AAA)?

Management of Abdominal Aortic Aneurysm (AAA)

The management of AAA should follow a size-based approach with surgical or endovascular repair indicated for men with AAA ≥5.5 cm and women with AAA ≥5.0 cm, while smaller aneurysms should undergo regular surveillance imaging. 1, 2

Diagnosis and Screening

• One-time screening is recommended for:

  • Men ages 65-75 who have ever smoked 1, 2
  • Consider screening for men ages 65-75 who have never smoked 1, 2
  • Men ≥60 years who are siblings or offspring of AAA patients 2
  • Not recommended for women who have never smoked 1

• Imaging modalities:

  • Ultrasound is preferred for initial screening and surveillance (cost-effective, no radiation) 1, 2
  • CT is recommended when ultrasound is inadequate or for preoperative planning 1
  • MRI is reasonable when CT is contraindicated 1

Surveillance Protocol

AAA Diameter	Recommended Surveillance Interval
3.0-3.4 cm	Every 3 years
3.5-3.9 cm	Every 2 years
4.0-4.4 cm	Every 12 months
4.5-5.4 cm (men)/4.5-4.9 cm (women)	Every 6 months

1, 2

Indications for Intervention

Absolute Indications:

• AAA ≥5.5 cm in men 1, 2
• AAA ≥5.0 cm in women 1, 2
• Symptomatic AAA (regardless of size) 2
• Rapid growth (>0.5 cm/year) 2

Risk Factors for Rupture (Consider Earlier Intervention):

• Female sex 2
• Continued smoking 2
• Uncontrolled hypertension 2
• COPD 2
• Saccular morphology 2

Treatment Options

1. Medical Management (For Small AAAs)

• Aggressive blood pressure control targeting SBP 120-129 mmHg 2
• Statin therapy for all AAA patients (inhibits aneurysm expansion) 2
• Smoking cessation (smokers have double the rate of aneurysm expansion) 2
• Beta-blockers to reduce shear stress on the aortic wall 2
• Lipid management (LDL-C <1.4 mmol/L or 55 mg/dL) 2

2. Surgical Options (For AAAs Meeting Size Criteria)

Open Surgical Repair

• Indicated for:
  • Good or average surgical candidates 1
  • Patients with anatomy unsuitable for endovascular repair 2
  • Patients with life expectancy >2 years who cannot comply with long-term surveillance 2

Endovascular Aneurysm Repair (EVAR)

• Indicated for:
  • Patients at high risk for complications from open surgery 1
  • Preferred first-line treatment when anatomy is suitable 2
  • Reduces perioperative mortality to <1% compared to open repair 2

Post-Repair Surveillance

• After EVAR:

  • Imaging at 6-12 months post-procedure 2
  • Annual surveillance for at least 5 years 2
  • Monitor for endoleaks (present in up to one-third of cases) 2
  • Immediate intervention for type I and type III endoleaks 2

• After open repair:

  • Less intensive follow-up required compared to EVAR 1

Complications and Outcomes

• EVAR vs. Open Repair:

  • EVAR has lower perioperative mortality but similar long-term mortality 2
  • EVAR has higher rates of reintervention (5.1% vs. 1.7%) 2
  • Rupture risk is significantly reduced with both approaches 1

• Untreated AAA rupture has 75-90% mortality rate 2

Key Considerations

• Small AAAs (4.0-5.5 cm) show no advantage to immediate repair over surveillance, regardless of whether open or endovascular repair is used 3
• The decision between open and endovascular repair should consider patient anatomy, comorbidities, and ability to comply with follow-up 1, 2
• Elective AAA repair is not recommended if life expectancy is <2 years 2

By following this evidence-based approach to AAA management, clinicians can optimize outcomes and minimize the risk of rupture while avoiding unnecessary interventions for small, stable aneurysms.