From the Guidelines
This 76-year-old male with a family history of AAA should undergo another screening scan due to the increased risk of developing an AAA with age, despite a normal scan at age 60. The risk of AAA increases with age, particularly after 65 years, and having a family history is a significant risk factor 1. Given that it has been 16 years since his last evaluation, which exceeds the recommended interval for reassessment in high-risk individuals, a follow-up scan is warranted.
The American College of Radiology suggests that imaging surveillance for AAA provides two primary purposes: identifying interval growth beyond the threshold for elective repair and monitoring the growth trajectory to identify a potentially increasing rate of growth 1. Although there is no consensus on the optimal maximum AAA diameter or the time intervals between ultrasound surveillance examinations, ongoing surveillance is crucial for individuals with risk factors such as family history.
Key considerations for this patient include:
- Age: The patient is 76 years old, and the risk of AAA increases with age.
- Family history: A significant risk factor for developing AAA.
- Time since last evaluation: 16 years, which exceeds the recommended interval for reassessment in high-risk individuals.
- Recommended screening method: Abdominal ultrasound, which is non-invasive and relatively inexpensive.
Based on the most recent evidence from the Journal of the American College of Radiology 1, the patient should undergo an abdominal ultrasound to assess for the presence of an AAA, and further management should be individualized based on the results and the patient's overall health status and life expectancy.
From the Research
Screening for Abdominal Aortic Aneurysm (AAA)
- The United States Preventive Services Task Force recommends that men between the age of 65 to 75 years who have ever smoked should be screened at least once for AAAs by abdominal ultrasonography 2, 3.
- For men with a family history of AAA, the risk of developing an AAA is increased, and screening is recommended 4.
- In this case, the 76-year-old male with a family history of AAA had a normal scan at the age of 60, but considering his age and family history, another scan may be necessary to monitor for potential development of an AAA.
Factors Influencing the Decision to Screen for AAA
- Age: The risk of AAA increases dramatically in men older than 60 years 2.
- Family history: A positive family history is a significant risk factor for AAA 4.
- Smoking: Smoking is a major risk factor for AAA, and screening is recommended for men who have ever smoked 2, 3.
Imaging Modalities for AAA Screening
- Abdominal ultrasonography is the preferred modality for screening and monitoring AAA due to its high sensitivity, specificity, safety, and relatively lower cost 2, 3, 5.
- Contrast-enhanced CT angiography is considered the gold standard for preoperative imaging and image-based treatment planning in AAA repair 5.
- Non-contrast MR angiography allows for accurate monitoring of aortic diameters in AAA patients 5.