Overview
Definition
A focal dilation of the abdominal aorta to ≥ 3.0 cm, typically occurring below the renal arteries.
Epidemiology
Common in older men with a history of smoking. Rupture carries an 80-90% mortality rate.
Etiology & Risk Factors
- Atherosclerosis and degeneration of the aortic wall media
- Smoking (strongest modifiable risk factor)
- Advanced age, male sex
- Hypertension
Clinical Symptoms
- Unruptured: Usually asymptomatic (found incidentally)
- Ruptured: Classic triad of severe sudden abdominal/flank pain, pulsatile abdominal mass, and hypotension/shock
Clinical Approach
Diagnosis
- Abdominal Ultrasound (initial test of choice for screening and diagnosis)
- CT Angiography (CTA) for preoperative planning or suspected rupture
Management
- Screening: One-time ultrasound for men 65-75 who have ever smoked
- Medical: Smoking cessation, Aspirin, Statins, BP control
- Surgical: Endovascular Aneurysm Repair (EVAR) or Open surgical repair if diameter > 5.5 cm (men) or > 5.0 cm (women), or if expanding > 0.5 cm in 6 months
Complications
- Aortic Rupture (massive internal hemorrhage)
- Distal atheroembolism ('blue toe syndrome')
- Aortoenteric fistula (rare but fatal GI bleed)