AAA stands for Abdominal Aortic Aneurysm, and as I have often pointed out, we
doctors love acronyms. I am sure that the education bodies decreed years ago
that the medical course should contain three years of acronyms, as well as
another three years of clinical practice.
So what is an abdominal aortic aneurysm (AAA)? First off,
what is the aorta? The aorta is the main artery of the body, directly connected
to the heart and taking the vast majority of the blood from that important
central pump to the abdominal organs and the legs. This artery is around 2 cm in
diameter.
However, a situation can occur, whereby the artery begins to
bulge and can grow to four or five times the normal diameter. It is this
swelling that is called an ‘aneurysm’. Being of the Abdominal Aorta, then
explains the AAA description. An aorta is considered ‘aneurysmal’ when it grows
more than 50 percent over its normal size. By the way, aneurysms may occur in
any blood vessel in the body, but the most common place is in the abdomen below
the renal arteries (the blood vessels that provide the blood to your kidneys).
Interestingly, aneurysms are four times more common in men than women and occur
most often after 55-60 years of age. Elderly males have yet another aspect to
monitor, as well as their prostates!
The danger of the AAA comes from the fact that this can
burst, like an over-inflated balloon, and the patient experiences a catastrophic
internal hemorrhage. This is generally fatal. Aneurysm rupture affects
approximately 15,000 people per year making it the 13th leading cause of death
in the US. The incidence of aortic aneurysm increases every decade as the
population ages. Fortunately, early detection and diagnosis is increasingly
possible as more sophisticated medical screening methods become available.
So why does this aneurysm occur? Aneurysms are caused by a
weakening or damage in the wall of a blood vessel. There are many conditions
known to contribute to the weakening of the artery wall including
atherosclerosis (hardening of the arteries), cigarette smoking, high blood
pressure and inflammation or infection.
Atherosclerosis (hardening of the arteries) is the most
common cause of abdominal aortic aneurysms. This occurs when substances such as
cholesterol, minerals, and blood cells build up in the walls of the artery, and
thus damaging it. The muscular wall of the aorta weakens and with the pressure
inside the artery, it begins to bulge. High blood pressure may speed up the
weakening, but it is not the cause. Aneurysms also tend to run in families, so
there is the thought that genetics may play a role in who gets an aneurysm.
(When in doubt, blame your parents - for everything!)
There is a strong link between cigarette smoking and the
occurrence of aneurysms. Smokers die four times more often from ruptured
aneurysms than nonsmokers. Aneurysms in smokers also expand and weaken faster
than those in nonsmokers, making this the one hundred and twenty thousandth good
reason to give up cigarettes.
Unfortunately, until an AAA bursts, there are generally no
symptoms to let you know you have one of these ‘time bombs’ sitting in your
belly. The discovery is then usually during an annual physical, where it can be
palpated by the doctor, but by far more accurate is an ultrasound, which can
give exact dimensions, and thus progressive indication of how rapidly the
swelling is growing.
The answer to this is an operation to replace the swollen,
weakened artery, with a suitable piece of highly expensive ‘garden hose’ of
correct length and diameter. This is a major operation, but once you have had an
AAA detected, there is no other way around the problem. There is also some work
being done on encasing the aorta to contain the swelling, but this is not the
usual method of ‘defusing’ an AAA.
You should be lining up for a routine health check every 12
months, after you reach 40 years of age. When was your last one?
However, if they do find one, you join the ranks of the
famous, as Einstein had one, but unfortunately died when it ruptured.
