Abdominal Aortic Aneurysm or AAA


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.