Read more about this disease, some with Classification – Types – Signs and symptoms – Genetics – Pathophysiology – Diagnosis – Screening – Prevention – Treatment and management – Cures and much more, some including pictures and video when available.
Abdominal aortic aneurysm, also written as AAA and often pronounced ‘triple-A’, is a localized dilatation of the abdominal aorta, that exceeds the normal diameter by more than 50%. The normal diameter of the infrarenal aorta is 2 cm. It is caused by a degenerative process of the aortic wall, but the exact etiology remains unknown. It is most commonly located below the kidneys (infrarenally; 90%), other possible locations are above or at the level of the kidneys (suprarenal and pararenal). The aneurysm can extend to include one or both of the iliac arteries. An aortic aneurysm may also occur in the thorax.
An abdominal aortic aneurysm occurs most commonly in older individuals (between 65 and 75), and more in men and smokers. There is moderate evidence to support screening in individuals with these risk factors. The majority of abdominal aortic aneurysms do not cause symptoms. Symptomatic and large aneurysms (>5.5 cm in diameter) are considered for repair.
The most important complication of an abdominal aortic aneurysm is rupture, which is most often a fatal event. An abdominal aortic aneurysm weakens the walls of the blood vessel, leaving it vulnerable to bursting open, or rupturing, and spilling large amounts of blood into the abdominal cavity.[1]
The first historical records about AAA are from Ancient Rome in the 2nd century AD, when Greek surgeon Antyllus tried to treat the AAA with proximal and distal ligature, central incision and removal of thrombotic material from the aneurysm. However, attempts to treat the AAA surgically were unsuccessful until 1923. In that year, Rudolph Matas (who also proposed the concept of endoaneurysmorrhaphy), performed the first successful aortic ligation on a human.[2] Other methods that were successful in treating the AAA included wrapping the aorta with polyethene cellophane, which induced fibrosis and restricted the growth of the aneurysm. Albert Einstein was operated on by Rudolf Nissen with use of this technique in 1949, and survived five years after the operation.[3]
AAA is uncommon in individuals of African, Asian, and Hispanic heritage.
The frequency varies strongly between males and females. The peak incidence is among males around 70 years of age, the prevalence among males over 60 years totals 2-6%. The frequency is much higher in smokers than in non-smokers (8:1), and the risk decreases slowly after smoking cessation.[4] Other risk factors include hypertension and male sex.[5] In the U.S., the incidence of AAA is 2-4% in the adult population. [6]. AAA is 4-6 times more common in male siblings of known patients, with a risk of 20-30%.[7]
Rupture of the AAA occurs in 1-3% of men aged 65 or more, the mortality is 70-95%.[8]
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