A Disease That Hides Until It's Too Late
The abdominal aorta is the largest artery in the body. When part of its wall weakens, it can balloon outward — an abdominal aortic aneurysm (AAA). Most AAAs cause no symptoms until they rupture, at which point mortality exceeds 80 percent.
The remarkable thing about AAA is how easy it is to find before catastrophe. A single ultrasound — quick, painless, no radiation, no IV — reliably identifies aneurysms while they are still safely treatable. Despite this, many men who would benefit from screening have never had one.
At Zimmer Medical Group, we screen eligible patients in accordance with current US Preventive Services Task Force guidelines, and the test is covered by Medicare for qualifying patients.
What Is an Aortic Aneurysm
The normal abdominal aorta is roughly 2 cm in diameter. An aneurysm is generally defined as a permanent enlargement to 3 cm or more. Aneurysms are categorized:
- Small: 3.0–4.4 cm
- Medium: 4.5–5.4 cm
- Large: ≥ 5.5 cm (the threshold where elective repair is typically recommended in men)
The risk of rupture rises sharply with size. Small aneurysms have very low rupture risk and are managed with surveillance. Large aneurysms warrant repair before they rupture.
Who Should Be Screened
The USPSTF recommendations:
- Men ages 65–75 who have ever smoked: one-time screening ultrasound (Grade B recommendation)
- Men ages 65–75 who have never smoked: selective screening based on individual risk factors and shared decision-making (Grade C)
- Women ages 65–75 who have ever smoked: evidence is less clear; selective screening based on individual risk and shared decision-making (Grade I)
- Women who have never smoked: screening not recommended
Major risk factors that lower the threshold for screening:
- Smoking history (the strongest modifiable risk factor)
- Family history of AAA, particularly in a first-degree relative
- Male sex
- Older age
- White race
- Other atherosclerotic disease — coronary artery disease, PAD, carotid disease
- Hypertension
- Hyperlipidemia
- Connective tissue disorders (Marfan, Ehlers-Danlos)
Family history matters significantly: a first-degree relative with AAA increases your risk by roughly 2–4 times.
Why Smoking Matters So Much
Smoking is by far the strongest modifiable risk factor for AAA. Patients with significant smoking history have 5–7 times the AAA risk of never-smokers. The risk persists for decades after quitting, though it gradually decreases. This is why USPSTF guidelines specifically prioritize men who have ever smoked — even those who quit decades ago.
Quitting smoking after AAA is diagnosed is one of the most important interventions to slow growth and reduce rupture risk.
What the Screening Test Involves
Abdominal ultrasound for AAA is:
- Performed in 15–20 minutes
- Painless and non-invasive
- Requires no radiation or IV contrast
- Usually done after fasting overnight (improves visibility)
- Covered by Medicare under the "Welcome to Medicare" exam for eligible patients
- Covered by most commercial insurance for qualifying patients
The technician measures the maximum diameter of the abdominal aorta. The radiologist generates a report; your primary care doctor reviews and discusses the result.
Interpreting Results
- < 3.0 cm: Normal. No further screening recommended for most patients.
- 3.0–3.9 cm: Small aneurysm. Repeat ultrasound every 2–3 years.
- 4.0–4.9 cm: Moderate aneurysm. Repeat every 6–12 months.
- 5.0–5.4 cm: Larger aneurysm. Repeat every 3–6 months, vascular surgery consultation.
- ≥ 5.5 cm in men, ≥ 5.0 cm in women: Threshold for elective repair in most patients.
- Rapid growth (> 0.5 cm in 6 months): Vascular surgery referral regardless of size.
The growth rate varies significantly between aneurysms. Surveillance allows timely intervention without rushing to surgery prematurely.
Treatment Options
For aneurysms reaching repair threshold:
Endovascular Aneurysm Repair (EVAR)
- Catheter-based procedure
- Stent graft inserted through the femoral artery
- Excludes the aneurysm from blood flow
- Shorter hospital stay and faster recovery
- Requires lifelong surveillance imaging
- The most common approach in modern practice
Open Surgical Repair
- Traditional open abdominal procedure
- The aneurysm is replaced with a graft
- Longer recovery but more durable, with less long-term surveillance needed
- Preferred for younger patients with longer life expectancy or unfavorable anatomy for EVAR
The choice depends on patient anatomy, age, comorbidities, and preferences. Both approaches are highly effective.
Medical Management Between Screenings
For patients with small or moderate aneurysms under surveillance:
- Smoking cessation is the single most impactful intervention — slows growth and reduces rupture risk
- Aggressive blood pressure control — typically ACE inhibitors or ARBs as first-line
- Statin therapy — slows growth and addresses concurrent cardiovascular risk
- Antiplatelet therapy — usually aspirin
- Cardiovascular risk factor optimization — diabetes, cholesterol, weight, physical activity
Symptoms That Demand Emergency Evaluation
Most AAAs are silent. Symptomatic AAA — and particularly rupture — is a medical emergency. Call 911 for:
- Sudden severe abdominal, back, or flank pain
- Pain radiating to the groin or legs
- A pulsating mass in the abdomen
- Sudden lightheadedness or fainting
- Signs of shock — pale, sweaty, weak pulse
Time is critical. Even with prompt surgery, ruptured AAA mortality remains very high.
A One-Time Test With Lifelong Implications
For an eligible patient, AAA screening is among the highest-yield single tests in medicine. A normal ultrasound provides reassurance for years. An abnormal result triggers surveillance that catches the aneurysm before it ruptures. The test is quick, free or low-cost for most eligible patients, and has saved many lives.
If you are a man between 65 and 75 with any history of smoking — or have a strong family history regardless of sex — and have never been screened, that is a conversation to have at your next appointment.
The Society for Vascular Surgery provides additional patient education on AAA screening and treatment.
Eligible for AAA screening but never had it done? Contact Zimmer Medical Group to discuss screening, schedule the ultrasound, and address the broader cardiovascular risk picture in one visit.
