natural history of abdominal aortic aneurysm (AAA)
Last reviewed 01/2018
Natural history of the condition is characterised by progressive expansion. The risk of rupture increases with the increase in size of the aneurysm (1).
Risk factors associated with expansion and rupture of AAA includes (2):
- expansion
- advanced age
- severe cardiac disease
- previous stroke
- tobacco use
- cardiac or renal transplant
- rupture
- female gender
- large initial aneurysm diameter
- low forced expiratory volume in one second (FEV1)
- higher mean blood pressure
- current tobacco use (length of time smoking>>amount)
- cardiac and renal transplant
Growth rates for AAA (3):
|
aneurysm diameter |
average annual expansion rate |
|
3.0 to 3.9 cm |
1 to 4 mm |
|
4.0 to 6.0 cm |
3 to 5 mm |
|
> 6.0 cm |
7 to 8 mm |
Absolute risk of rupture for AAA (3):
aneurysm diameter |
absolute lifetime risk of rupture |
|
5 cm |
20% |
|
6 cm |
40% |
|
7 cm |
50% |
Reference:
- (1) Kent KC. Clinical practice. Abdominal aortic aneurysms. N Engl J Med. 2014;371(22):2101-8
- (2) Chaikof EL et al. The care of patients with an abdominal aortic aneurysm: the Society for Vascular Surgerypractice guidelines. J Vasc Surg. 2009;50(4 Suppl):S2-49
- (3) Keisler B, Carter C. Abdominal aortic aneurysm. Am Fam Physician. 2015;91(8):538-43.