Abdominal aortic aneurysm resident survival guide
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief:
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Overview
Abdominal aortic aneurysm (AAAs) are defined as abnormal dilation of abdominal aorta, mostly in infrarenal part of aorta with extension to iliac arteries, up to more than 3 cm in the greatest diameter or dilatation of more than 50% of its diameter. Aneurysm is related to regional weakening of vessels wall structure. Although AAAs are more common in men than women, women with AAAs have worse prognosis than men. The predisposing factors include male gender, age >75 years, prior vascular disease, hypertension, smoking, family history of cardiovascular disease, hypercholesterolemia. The incidence of AAAs has continued to rise, of which they remain the leading cause of death in USA. Most AAAs are usually asymptomatic and detected accidentally. Unruptured aneurysms may present mild abdominal or back pain with pulsatile mass while ruptured aneurysms cause severe abdominal or back pain, hypotension and shock and they are associated with high mortality. AAAs are attributed to primary and secondary aneurysm. Primary aneurysms relate to defects in vessel wall (i.e. fibrillin deficiency or collagen III deficiency). Secondary aneurysms relate to turnover and pathological vessel wall remodelling. Imaging is vital for detection of AAAs. Abdominal X-ray and ultrasound are performed to detect AAAs. However, ultrasound is simple, safe and inexpensive with sensitivity of 95% and specificity close to 100%. CT angiography is another imaging option which is the gold standard in evaluation of aortic size and extension of aneurysm, though it has high radiation doses.
Causes
Life Threatening Causes
Acute ruptured AAAs are surgical emergencies and if left untreated, it has a mortality rate approaching 100%.
Common Causes
- Atherosclerosis is the most common cause
- Vasculitis
- Marfan syndrome
- Ehlers-Danlos syndrome
- Mycotic aneurysm
- Traumatic pseudoaneurysm
Screening
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Treatment
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Do's
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Don'ts
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