SUMMARY:

In December 2019, the USPSTF updated the 2014 recommendations for screening asymptomatic adults for abdominal aortic aneurysm (AAA), based on 4 large population-based clinical trials

A newly added feature is the importance of family history (first degree relative) of AAA as a risk factor for screening decision in women

USPSTF recommends the following

Men 65 to 75 years who have ever smoked

Recommendation Grade B (offer or provide this service)

• One-time screening ultrasound   
  • Magnitude of net benefit of screening is moderate | Harms are small to moderate
• Ever smoker “commonly defined as ≥100 cigarettes”

Men 65 to 75 years who have never smoked

Recommendation Grade C (offer or provide this service for selected patients depending on individual circumstances)  

• Selectively offer one-time screening ultrasound rather than routinely to all men in this age group
• Magnitude of net benefit of screening is small | Harms are small to moderate
• Consider
  • Medical history | Family history | Other Risk Factors | Personal values

Women who have never smoked and have no family history of AAA

Recommendation Grade D (discourage the use of this service) 

• “Adequate evidence” that there is no benefit to screening ultrasound| Harms are small to moderate
• Moderate certainty that harms outweigh benefits

Women 65 to 75 years who have ever smoked or have a family history of AAA

I Statement (if the service is offered, patients should understand the uncertainty about the balance of benefits and harms)

• The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of the service. Evidence is lacking, of poor quality, or conflicting, and the balance of benefits and harms cannot be determined
  • Abdominal aortic aneurysm – there may be greater potential to prevent serious adverse outcomes
    • Compared to men, women with small AAAs have an increased risk of rupture
    • Approximately 25% to 33% of women have AAA with a diameter <5.5 cm surgical threshold at the time of rupture
  • However, women also experience higher risk of harms
    • Higher operative mortality | Longer hospital stay | Higher readmission rate       

KEY POINTS:

• AAA is defined as aortic enlargement with a diameter of ≥3.0 cm
• Due to the low uptake of screening in the USA the prevalence is unclear
• Recommendations are stratified by “men” and “women”
  • Benefit vs risk estimates are driven by biologic sex (ie, male/female) rather than gender identity
  • Persons should consider their sex at birth to determine which recommendation best applies to them
• Risk factors
  • Older age
  • Male sex
  • Smoking
  • First degree relative with AAA
  • Other vascular aneurysms | CAD | CAD | Cerebrovascular disease | Atherosclerosis | Hypercholesterolemia | Hypertension
• Protective factors
  • African American race | Hispanic ethnicity | Asian ethnicity | Diabetes  

Note: Above are risk factors for AAA | Risk factors for actual rupture include older age, female, smoking, and elevated BP                                             

Ultrasound Screening for AAA

• Screening test is a conventional abdominal duplex ultrasonography
• Screening intervals
  • 3 to 4 cm diameter: Reimage once a year
  • 4 to 5 cm diameter:  Reimage every 6 months
  • Enlargement > 5 cm within 6 months should be considered at high risk for rupture

Treatment for AAA

• Balance of risk of rupture vs operative mortality
• Most common approach is endovascular aneurysm repair (EVAR)
• Elective repair
  • Men: Diameter ≥5.5 cm
  • Women: 5.0 to 5.4 cm (Society for Vascular Surgery)

Recommendations by Other Organizations

ACC and AHA

• Recommend one-time screening for AAA with physical examination and ultrasonography for  
  • Men 65 to 75 years who have ever smoked
  • Men ≥60 years are the sibling or offspring of a person with AAA
• Do not recommend screening for
  • AAA in men who have never smoked
  • Women

The Society for Vascular Surgery

• Recommends one-time ultrasonography screening for
  • All men and women 65 to 75 years with a history of tobacco use
  • Men ≥55 years with a family history of AAA
  • Women ≥65 years who have smoked or have a family history of AAA 

The American College of Preventive Medicine

• Recommends one-time screening for
  • Men 65 to 75 years who have ever smoked
• Does not recommend
  • Routine screening in women

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Learn More – Primary Sources:

Primary care screening for abdominal aortic aneurysm: evidence report and systematic review for the US Preventive Services Task Force

Primary Care Screening for Abdominal Aortic Aneurysm Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

Open versus endovascular repair of abdominal aortic aneurysm