A Physician’s Reference for Abdominal Aortic Aneurysm (AAA)
By Dr. Bryan Kramer and Taylor Caddell, RVU MSIII - December 30, 2019
Screening and Diagnosis
- Abdominal aortic aneurysms are dilations of the abdominal aorta, usually occurring below the renal arteries and above the aortic bifurcation.
- Risk factors for AAA include male gender, advanced age, smoker or former smoker, hypertension, or a family history of AAA.
- AAAs are often incidentally diagnosed on physical exams or abdominal scans for other reasons. 95% of patients without aneurysm will have an abdominal aortic diameter of less than 3cm. If the diameter is larger than 3cm, an AAA is diagnosed.
- USPTF recommends one-time screening for AAA with ultrasound for men aged 65-75 who have ever smoked.
- We also recommend screening for women over 65 who have smoked in their past.
Symptomatic Management and Surgical Intervention
- The management of asymptomatic AAA is based upon the risk of rupture of the aneurysm versus the risk of intervention. Once the risk of rupture is greater than the perioperative risk, intervention is recommended. This risk of rupture is assessed through the diameter of the aneurysm at diagnosis, the rate of expansion, and patient comorbidities. Yearly (or even more frequent given the patient’s risk for expansion) abdominal ultrasounds are recommended for surveillance of the aneurysm. In general, elective repair should be considered at 5cm in men and 4.5cm in women.
- Smoking cessation has shown to be the most important modifiable risk factor for expansion of the aneurysm. Hypertension management is also recommended.
- Medications: It is recommended that fluoroquinolones be avoided in these patients, unless there is no other suitable antibiotic therapy.
- Most patients with AAA are asymptomatic. However, some will present with abdominal/back pain or limb ischemia. These symptoms are dependent on the size and location of the aneurysm.
- Urgent surgical intervention is recommended for symptomatic patients if no other cause of the symptoms can be identified. Likewise, any sign of rupture (back/flank pain, pulsatile abdomen, hypotension) is an indication for immediate surgical intervention.
- Vascular surgeons consider endovascular (stent) and open surgical repair for patients who require intervention. The choice of intervention is based on patients age, comorbidities, life expectancy, patient preference if possible, and individual aortic anatomy.