From the Guidelines
For an abdominal aortic aneurysm (AAA) measuring 3 cm in the upper abdominal aorta, surveillance ultrasound should be performed every 2-3 years. This recommendation is based on the relatively low risk of rupture for aneurysms of this size, as stated in the study by 1. The study highlights that the risk of rupture is lower for small AAAs, and surveillance is indicated for patients with small AAA (males, diameter 3-5.4 cm, and females, diameter 3-4.9 cm).
Key considerations for surveillance include:
- The intervals between US surveillance examinations depend on aneurysm size 1
- Imaging surveillance provides two primary purposes: to identify interval growth beyond the threshold for elective repair and to monitor the growth trajectory and identify a potentially increasing rate of growth 1
- Growth rates >2 mm per year are associated with increased adverse events 1
If the patient has risk factors for more rapid growth, such as smoking, hypertension, or family history of AAA, consider surveillance at the shorter 2-year interval. During follow-up visits, patients should be advised to quit smoking if applicable, as smoking accelerates aneurysm growth. Blood pressure should be optimally controlled, typically aiming for levels below 140/90 mmHg using appropriate antihypertensive medications.
Monitoring and follow-up are crucial, and the surveillance interval should be shortened to yearly if the aneurysm grows to 4-4.5 cm. If it reaches 5-5.5 cm or grows more than 0.5 cm in a year, referral to a vascular surgeon is warranted for consideration of repair, as stated in the guidelines 1. This surveillance approach balances the need to monitor for potentially dangerous growth while avoiding unnecessary testing for a condition that poses relatively low risk at the 3 cm size.