What are the guidelines for abdominal aortic aneurysm (AAA) screening in previous smokers?

AAA Screening Guidelines for Previous Smokers

Men ages 65 to 75 who have ever smoked (defined as at least 100 cigarettes in their lifetime) should receive a one-time screening for abdominal aortic aneurysm (AAA) with ultrasonography. 1, 2

Screening Recommendations by Population

Men

• Men ages 65 to 75 who have ever smoked should undergo one-time screening for AAA with ultrasonography (Grade B recommendation) 1, 2
• Men ages 65 to 75 who have never smoked may be selectively offered screening rather than routinely screening all men in this group (Grade C recommendation) 1
• For men with a family history of AAA, screening is recommended for first-degree relatives of patients with AAA aged ≥50 years, regardless of smoking status 3
• Screening may be considered in men aged ≥75 years irrespective of smoking history 3

Women

• The USPSTF has issued an "I Statement" indicating insufficient evidence to assess the balance of benefits and harms of screening in women ages 65-75 who have ever smoked 4, 5
• Women who have never smoked should not get routine AAA screening (Grade D recommendation) 1, 4
• Screening may be considered in women aged ≥75 years who are current smokers, hypertensive, or both 4
• Women with a family history of AAA may benefit from screening, though evidence is less certain than for men 1

Rationale for Screening Former Smokers

• The prevalence of AAA is significantly higher in men who have ever smoked compared to those who have never smoked 1, 6
• One-time screening with ultrasound, along with appropriate treatment, can reduce the risk of dying from a ruptured AAA by about half in men ages 65-75 who have ever smoked 1
• Among men age 65 to 74 years, an estimated 500 who have ever smoked would need to be screened to prevent 1 AAA-related death in the next 5 years 1
• The definition of "ever smoker" is a person who has smoked at least 100 cigarettes in his or her lifetime 1

Screening Method and Follow-up

• AAA screening is performed using abdominal ultrasonography, which is safe, painless, and has high sensitivity and specificity 1, 2, 7
• Ultrasonography should be performed in an accredited facility with credentialed technologists to ensure adequate quality assurance 1, 2
• One-time screening is sufficient for those with normal aortic diameter on initial screening 3
• For small aneurysms (less than 5.5 cm in diameter), periodic monitoring with ultrasound is typically recommended 1, 2
• Surgical intervention is generally recommended for aneurysms 5.5 cm or larger, or those growing rapidly 1, 2

Risk Factors to Consider

• Major risk factors for AAA include age (≥65 years), male sex, and a history of ever smoking 1, 6
• Additional risk factors include family history of AAA, coronary artery disease, hypertension, peripheral artery disease, and previous myocardial infarction 6
• First-degree family history of AAA requiring surgical repair significantly elevates risk 1, 3
• The risk of rupture is influenced by aneurysm size, expansion rate, continued smoking, and persistent hypertension 7

Potential Benefits and Harms

• Benefits: Early detection and treatment of large AAAs can reduce AAA-specific mortality 1
• Harms: Increased number of surgeries with associated morbidity and mortality, and short-term psychological harms 1
• The balance between benefits and harms favors screening in men 65-75 who have ever smoked 1, 5

Common Pitfalls

• Underutilization of screening in the target population of men 65-75 who have ever smoked 8
• Overly broad application of screening beyond evidence-based recommendations may reduce cost-effectiveness 8, 9
• Failure to recognize that recommendations are based primarily on studies of men; evidence for women is less robust 4, 5
• Not accounting for family history as an independent risk factor that warrants screening 1, 3