When should screening for Abdominal Aortic Aneurysm (AAA) be performed in an older adult male with a history of smoking?

AAA Screening Timing

Men aged 65-75 years with any history of smoking should receive one-time ultrasound screening for abdominal aortic aneurysm. 1, 2

Primary Screening Recommendations

Men with Smoking History (Strongest Evidence)

• One-time ultrasound screening is recommended for all men aged 65-75 years who have ever smoked (defined as lifetime smoking of >100 cigarettes or equivalent), as this reduces AAA-specific mortality by approximately 50%. 1, 2, 3
• This represents a Grade B recommendation from the U.S. Preventive Services Task Force, indicating moderate certainty of moderate net benefit. 2, 4
• The European Society of Cardiology specifically recommends screening in men aged ≥65 years with smoking history to reduce risk of death from ruptured AAA. 1

Men Without Smoking History

• Men aged 65-75 years who have never smoked may be selectively offered screening rather than routine screening, particularly if other risk factors are present (family history, coronary artery disease, peripheral arterial disease). 2, 4, 5
• Men aged ≥75 years without smoking history may be considered for screening, though evidence is weaker. 1

Family History Screening (Critical Exception)

First-degree relatives of patients with AAA should be screened starting at age 50 years, unless an acquired cause can be clearly identified. 1, 2 This is a Class I recommendation from the European Society of Cardiology, reflecting the strong hereditary component of AAA. 1

Women Screening Considerations

• Women aged ≥75 years who are current smokers, hypertensive, or both may be considered for screening. 1
• Women who have never smoked should not receive routine AAA screening, as harms likely outweigh benefits. 2, 4, 5
• For women aged 65-75 with smoking history or family history of AAA, evidence remains insufficient for definitive recommendations. 2

Opportunistic Screening

Opportunistic AAA screening should be considered during transthoracic echocardiography in men aged ≥65 years and women aged ≥75 years. 1, 2 This represents an efficient approach to identify AAA without dedicated screening visits.

Screening Method

• Duplex ultrasound (DUS) is the recommended screening modality, with sensitivity and specificity approaching 100%. 1, 2, 3
• Ultrasonography should be performed in an accredited facility with credentialed technologists to ensure quality assurance. 2, 4
• Color Doppler is not required for screening but may be used as an adjunct. 2
• Ultrasound fails to visualize the aorta adequately in only 1-2% of cases due to bowel gas or anatomical challenges. 2

Common Pitfalls

• Underutilization remains a major problem, with screening rates in eligible populations only 13-26% despite clear mortality benefit. 2
• Not considering family history as an important risk factor that warrants screening outside standard age/smoking guidelines. 2
• One-time screening is sufficient—there is negligible benefit to repeat screening if initial aortic diameter is normal (<3.0 cm). 3

Post-Screening Management

• Normal aorta (<3.0 cm): No further AAA screening needed. 3
• Small aneurysms (<5.5 cm): Periodic monitoring with ultrasound is recommended. 2, 4
• Large aneurysms (≥5.5 cm) or rapid growth (>5 mm/6 months): Refer for surgical evaluation (open repair or endovascular repair). 3, 6