What are the screening guidelines for abdominal aortic aneurysm (AAA) in men over 65 years old with a history of smoking, hypertension, or atherosclerosis?

AAA Screening Guidelines

Primary Recommendations

Men ages 65-75 who have ever smoked (≥100 cigarettes lifetime) should receive one-time ultrasound screening for abdominal aortic aneurysm, as this reduces AAA-specific mortality by approximately 50%. 1, 2

Screening by Population Group

Men 65-75 years with smoking history:

• One-time ultrasonography screening is strongly recommended (Grade B) 1, 2, 3
• This is the highest-yield population for screening, with prevalence of AAA at 7.7% 4
• Screening reduces risk of death from ruptured AAA by 42-68% over 5-10 years 4

Men 65-75 years who have never smoked:

• Selective screening may be offered rather than routine screening for all (Grade C) 1, 2, 3
• AAA prevalence is much lower in this group, so benefits are limited 1, 3
• Clinical judgment should guide whether to screen based on other risk factors (hypertension, family history, atherosclerosis) 5, 6

Women 65-75 years who have ever smoked:

• Insufficient evidence to recommend for or against routine screening (Grade I) 1, 2
• Consider screening if strong family history of AAA is present 2
• Risk of surgical mortality is higher in women than men 1

Women who have never smoked:

• Do not screen routinely (Grade D) 1, 2, 3
• AAA is very rare in this population 1, 3

Special Populations Requiring Screening

First-degree relatives of AAA patients:

• Screen at age ≥50 years regardless of smoking status 2, 7
• Family history is an independent risk factor warranting screening 7

Opportunistic screening considerations:

• Women aged ≥75 years during transthoracic echocardiography, particularly if current smokers or hypertensive 2
• Men aged ≥75 years may be considered for screening irrespective of smoking history 7

Screening Method

Ultrasonography is the screening modality of choice:

• Sensitivity and specificity approach 100% 2, 5
• Safe, painless, and cost-effective 1, 3, 5
• Must be performed in accredited facility with credentialed technologists 2, 3
• Fails to visualize aorta adequately in only 1-2% of cases 2
• Color Doppler not required but may be used as adjunct 2

Management Based on Screening Results

Normal aorta (diameter <3 cm):

• No further surveillance needed 4
• Risk of developing clinically significant AAA over 10 years is only 4% 4
• Mortality from rupture is 1 per 1000 scans over 10 years 4

Small AAA (<5.5 cm in men, <5.0 cm in women):

• Periodic monitoring with ultrasound 1, 2, 3
• Medical management: smoking cessation and blood pressure control 8, 5, 6
• Cardiovascular risk factor modification 6, 9

Large AAA (≥5.5 cm in men, ≥5.0 cm in women) or rapidly growing (>5 mm/6 months):

• Surgical intervention generally recommended 1, 2, 3, 8, 6
• Options include open surgical repair or endovascular stent graft repair 8, 5
• Elective repair leads to 43% reduction in AAA-specific mortality 7

Common Pitfalls

Underutilization of screening:

• Only 13-26% of eligible populations are screened despite clear mortality benefit 2
• Actively identify and invite eligible men ages 65-75 with smoking history 6

Missing family history:

• Not considering family history as important risk factor that may warrant screening outside standard guidelines 2
• Always ask about first-degree relatives with AAA 7

Inadequate quality assurance:

• Ensure ultrasonography performed in accredited facilities to maintain diagnostic accuracy 2, 3