What is the recommended screening method for Abdominal Aortic Aneurysm (AAA)?

AAA Screening: Recommended Method and Approach

The recommended screening method for abdominal aortic aneurysm is one-time ultrasonography performed in an accredited facility with credentialed technologists. 1, 2

Screening Modality

Ultrasonography is the gold standard for AAA screening, with sensitivity of 95% and specificity approaching 100%. 3 This imaging modality uses sound waves to create pictures of the abdominal aorta and must be performed in quality-assured settings with proper accreditation and credentialed technologists to ensure accuracy. 1, 2

Who Should Be Screened

The screening algorithm is straightforward and based on age, sex, and smoking history:

Strong Recommendation (Grade B)

• Men aged 65-75 years who have ever smoked (current or former smokers) should receive one-time ultrasound screening. 1, 2 This reduces AAA-specific mortality by approximately 43-50%. 3

Selective Screening (Grade C)

• Men aged 65-75 years who have never smoked may be offered screening on an individual basis, particularly if they have additional risk factors including family history of AAA (first-degree relatives), coronary artery disease, hypertension, or peripheral artery disease. 1, 4

Insufficient Evidence (I Statement)

• Women aged 65-75 years who have ever smoked or have a family history of AAA: insufficient evidence exists to recommend for or against screening. 1, 2

Not Recommended (Grade D)

• Women who have never smoked should not undergo routine screening, as harms outweigh benefits. 1, 2

Special Populations Requiring Consideration

First-degree relatives (parents, siblings, children) of patients with AAA aged ≥50 years warrant screening consideration, as the lifetime prevalence of AAA in brothers of affected patients is estimated at 32%. 2, 3, 5

Frequency of Screening

One-time screening is sufficient—rescreening patients with normal initial results (aortic diameter <3.0 cm) provides negligible health benefit and should be avoided. 3, 5 The mean AAA growth rate is approximately 0.26 cm/year, which explains why repeat screening is unnecessary in those with normal initial results. 5

Management Based on Screening Results

The approach is size-dependent:

• Normal (<3.0 cm): No further screening needed 5
• Small AAA (3.0-3.9 cm): Periodic ultrasound surveillance without immediate intervention 3
• Intermediate AAA (4.0-5.4 cm): Surveillance preferred over immediate surgery, as randomized trials showed no mortality benefit from immediate repair 3
• Large AAA (≥5.5 cm in men, ≥5.0 cm in women): Surgical intervention indicated, either open repair or endovascular repair (EVAR) 2, 3

Common Pitfalls to Avoid

Do not perform routine rescreening in patients with normal initial results, as this creates unnecessary healthcare costs without proven mortality benefit. 5 Do not overlook family history as an important risk factor that may warrant screening outside standard age-based guidelines. 2 Do not screen women without smoking history, as the low prevalence in this population means harms exceed benefits. 1