What is an aneurysm?
What is the aorta?
What is an abdominal aortic aneurysm?
Why are abdominal aortic aneurysms
dangerous?
What is an aneurysm?
An
aneurysm is an abnormal, localized, blood-filled dilatation of a blood vessel. This is caused by disease, weakening or
trauma to the wall of the vessel. One of the commonest sites where aneurysms occur is in the abdominal aorta.
What is the aorta?
When blood leaves the heart, it enters the aorta (the largest blood vessel in the body). The aorta goes all the way
from the heart, through the chest and into the abdomen. At the level of the belly button it divides into 2 arteries (one for
each leg). During its course, the aorta gives a number of important branches to supply the head, arms, liver, stomach, bowels
and both kidneys. The normal aorta has a diameter of 1.5 to 2.5cm, depending on one's build.
What is an abdominal aortic aneurysm?
Aneurysms of the abdominal aorta are also called AAA (pronounced triple A). This stands for Abdominal Aortic Aneurysms.
Most AAA involve the aorta below where it gives off the branches to the kidneys. In just under a quarter of cases, the aneurysm
may also involve the artery on its way from the aorta to the groin. These aneurysms are known as aorto-iliac aneurysms. Less
commonly the aneurysm extends upwards to involve the blood vessels (arteries) to the kidneys. These aneurysms are known as
juxta-renal if they only extend up to the level of the renal (kidney) arteries, or supra-renal if they extend beyond this
level.
Why are abdominal aortic aneurysms dangerous?
Aneurysms are like silent bombs waiting to explode. The wall of the
aorta wears thin and starts to balloon out. This can be due to wear and tear but heavy smoking and fatty foods can contribute. Until
the aneurysm reaches 5cm in diameter (width), the risk of rupture is very small, but once it gets to 5.5cm the risk shoots
up.
AAA are usually asymptomatic. This means that there is nothing to warn
you that you have got this condition. The only warnings tend to come just before it bursts - and even then they are non-specific,
such as stomach ache or back pain. When the aneurysm ruptures, you'll usually die of internal bleeding and shock within a
few hours. If you can get to hospital, the survival rates are only around 50%
