Abdominal Aortic Aneurysm Screening (AAA)
Are you at risk for catastrophic aortic rupture?
Jun 2, 2008
Are you a male age 65 or older who smokes or has a past history of smoking? Then you need to discuss the risk of abdominal aortic aneurysm (AAA) with your physician. What is an AAA? An abdominal aortic aneurysm is a dilatation of 3.0 cm or greater in the abdominal aorta wall.
The vascular disease condition is common in men over 65 years of age. Incidence is 6% in men age 65 and increases by 6% with each additional decade. In 2005, Almahameed, et al. explored the incidence of AAA in "Managing abdominal aortic aneurysms: treat the aneurysm and the risk factors," published in the Cleveland Clinic Journal of Medicine. They report that men aged 65 have a 1% incidence of clinically significant AAAs and the incidence increases 2-4% each decade. This means by age 75 the risk of AAA is 12%, with as many as 5% of all men requiring clinical or surgical management.
Abdominal Aortic Aneurysm Catastrophic Rupture
Why should you be screened for AAA? AAAs grow larger over time. Nearly one third of patients with an AAA diameter greater than 5.5 cm will experience a catastrophic rupture. Most experiencing rupture cannot reach medical treatment rapidly enough. The US Preventive Services Task Force indicates the fatality rate of AAA rupture is 85-90%, with only 50% of those reaching the hospital surviving surgery and the remainder dying en route.
Risk Factors for Abdominal Aortic Aneurysm
- Male
- Age greater than 65 years
- Family history of AAA
- Hypertension
- Chronic Obstructive Pulmonary Disease (COPD)
- Artherosclerosis
- Smoking
Smoking is the strongest risk factor. Even if you smoked as few as 100 cigarettes in your lifetime and stopped smoking decades ago, you still have this risk factor.
Screening Guidelines for AAA Disease
- Male
- Age 65 years or older
- Current or former smoker
What should you expect from an abdominal aortic aneuysm screening?
If you meet all three of these criteria you should request a one-time ultrasonography screening for AAA. Sonograms are clinically noninvasive, relatively inexpensive, with nearly 100% sensitivity for AAAs. CT scans also accurately detect AAAs, but are more expensive and have risks associated with radiation exposure, kidney toxicity from contrast scan, and potential allergic reaction. Don’t settle for a physical exam; more than 20% of significant AAAs are missed.
Dilatations larger than 4.0 cm are clinically relevant and will require monitoring by repeat sonograms every six to twelve months. If an AAA is larger than 5.5 cm, the risk of rupture increases dramatically. Surgical repair with endovascular stent graft is indicated to prevent catastrophic rupture.
Reference:
Rubin, Dr. Robin N. “What’s The Take Home? Screening for Vascular Disease in a Former Smoker.” Consultant 48 (2008): 467-8.
 |
 |
