Abdominal aortic aneurysm overview: Difference between revisions
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==Risk Factors== | ==Risk Factors== | ||
The most | ===Abdominal Aortic Aneurysm Development=== | ||
The most significant modifiable risk factor for the development of an abdominal aortic aneurysm is smoking which increases the risk of aneurysm development 8 fold. Advanced age and family history are the strongest non-modifiable risk factors for the development of an abdominal aortic aneurysm. [[Hypercholesterolemia]] and [[hypertension]] are risk factors as well. Both [[diabetes mellitus]] and black race appear to be associated with a lower incidence of abdominal aortic aneurysm. | |||
===Abdominal Aortic Aneurysm Expansion=== | |||
An increased rate of expansion of abdominal aortic aneurysm is related to systolic [[hypertension]], [[wide pulse pressure]], and ongoing [[smoking]]. | |||
===Abdominal Aortic Aneurysm Rupture=== | |||
The risk of abdominal aortic aneurysm rupture is proportional to the size and rate of growth of the aneurysm. Abdominal aortic aneurysms greater than 5 cm diameter or those that grow faster than 1 cm per year have a significantly increased risk of rupture and are indications for elective operative repair. Advanced age, female gender, hypertension, active smoking, outpouchings, and mural thrombus are also risk factors for abdominal aortic aneurysm rupture. | |||
==Videos on Abdominal Aortic Aneurysm== | ==Videos on Abdominal Aortic Aneurysm== | ||
Revision as of 23:34, 27 October 2012
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Abdominal Aortic Aneurysm Microchapters |
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Differentiating Abdominal Aortic Aneurysm from other Diseases |
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Diagnosis |
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Treatment |
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Case Studies |
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Abdominal aortic aneurysm overview On the Web |
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Directions to Hospitals Treating Abdominal aortic aneurysm overview |
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Risk calculators and risk factors for Abdominal aortic aneurysm overview |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Associate Editor-In-Chief: Cafer Zorkun, M.D., Ph.D. [2]
Overview
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 of the abdominal aorta by more than 50%.
Historical Perspective
The etymology of the word aneurysm comes from the Greek word for "dilatation". Abdominal aortic aneurysm as a medical condition has been recognized since ancient times, but was not been successfully treated until the early part of the 20th century.
Definition
The normal diameter of one's aorta depends on the patient's age, sex, height, weight, race, body surface area, and baseline blood pressure. On average, the normal diameter of the infrarenal aorta (where abdominal aortic aneurysms are located) is 2 cm. Therefore an abdominal aortic aneurysm is defined as a dilation of 3.0 cm or more.
An abdominal aortic aneurysm is to be distinguished from aortic ectasia which is defined as a mild generalized dilatation (<50% of the normal diameter of ≤ 2.9 cm) that is due to age-related degenerative changes in vessel wall.
Anatomy
The aorta below the renal arteries, also known as the infrarenal aorta, is the location of 90% of abdominal aortic aneurysms. Other possible locations are suprarenal and pararenal. The aneurysm can extend to include one or both of the iliac arteries.
Classification
Aneurysms are usually classified by their shape:
Fusiform Aneurysms
- Most common type seen in the infrarenal aorta
- Diffuse, circumferential
Saccular Aneurysms
- Involve only a portion of the circumference, with a characteristic outpouching of the vessel wall.
Pathophysiology
The underlying pathophysiology of abdominal aortic aneurysm involves genetic influences, smoking, hypertension, hemodynamic influences and underlying atherosclerosis. In rare instances infection, arteritis, and connective tissue disorders may play a role.
Differentiating Abdominal Aortic Aneurysm from other Disorders
An abdominal aortic aneurysm should be differentiated from other causes of abdominal pain such as acute cholecystitis.
Epidemiology and Demographics
Abdominal aortic aneurysm is the 13th leading cause of death in the US. Abdominal aortic aneurysms are more common in developed countries. Elderly, caucasian males who are smokers are at higher risk for developing an abdominal aortic aneurysm.
Risk Factors
Abdominal Aortic Aneurysm Development
The most significant modifiable risk factor for the development of an abdominal aortic aneurysm is smoking which increases the risk of aneurysm development 8 fold. Advanced age and family history are the strongest non-modifiable risk factors for the development of an abdominal aortic aneurysm. Hypercholesterolemia and hypertension are risk factors as well. Both diabetes mellitus and black race appear to be associated with a lower incidence of abdominal aortic aneurysm.
Abdominal Aortic Aneurysm Expansion
An increased rate of expansion of abdominal aortic aneurysm is related to systolic hypertension, wide pulse pressure, and ongoing smoking.
Abdominal Aortic Aneurysm Rupture
The risk of abdominal aortic aneurysm rupture is proportional to the size and rate of growth of the aneurysm. Abdominal aortic aneurysms greater than 5 cm diameter or those that grow faster than 1 cm per year have a significantly increased risk of rupture and are indications for elective operative repair. Advanced age, female gender, hypertension, active smoking, outpouchings, and mural thrombus are also risk factors for abdominal aortic aneurysm rupture.
Videos on Abdominal Aortic Aneurysm
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References
Acknowledgements
The content on this page was first contributed by: C. Michael Gibson M.S., M.D. Template:WH Template:WS