What Is An Abdominal Aortic Aneurysm (AAA)?
If an artery weakens it will sometimes bulge out and expand. This enlarged
area is called an aneurysm. The most common site is in the abdominal aorta,
the large artery that carries blood from the heart through the abdomen
to the legs. Such an aneurysm is called an abdominal aortic aneurysm,
more commonly referred to as an AAA or "Triple A". Aneurysms
less commonly occur in the branches of the aorta that go to the legs (the
iliac arteries) and in the legs themselves where they enlarge the popliteal
artery behind the knee.
What is the significance of an Abdominal Aortic Aneurysm?
The main risk of an aneurysm is that it can rupture resulting in profuse
bleeding and often death. AAA causes more than 10,000 deaths in the USA
and many of these are preventable through early diagnosis and treatment.
Approximately 50,000 patients undergo surgery for AAA in the USA alone
every year. Once the AAA has ruptured, the chance of dying is 80-90% therefore
there are clear-cut reasons for screening for this problem.
Who is at risk for AAA?
After the age of 65 a man has a risk of approximately 7%, whereas it less
than 1% for a woman. By the age of 80 the risk is up to 10% for a male
vs. 2% for a woman. A person’s risk is also increased if a family
member had an AAA.
Smokers, patients with atherosclerosis "hardening of the arteries",
heart disease, and COPD/emphysema have the highest risk.
How are AAA's diagnosed?
Unfortunately, aneurysms frequently produce no symptoms before they leak
or rupture that would prompt a person to seek medical attention. But they
can be picked up at a regular physical examination. When an examining
doctor discovers signs suspicious of an abdominal aneurysm, an ultrasound
examination may reveal its size and location. More advanced tests, like
a CT scan and M.R.I., are usually included in the diagnostic workup.
Medicare will pay for AAA screening via the SAAAVE act. To be eligible,
you must be a male who has smoked in your lifetime or be a male or female
with a family history of AAA.
What is the treatment for AAA?
There is no medical treatment for aneurysms. In general people with small
aneurysms are encouraged to control blood pressure and treat conditions
that may accelerate atherosclerosis. Smoking must be stopped if possible.
Exercise is not restricted. Once the AAA has reached a certain size threshold
putting patients at risk for the AAA rupturing, the AAA should be repaired
via a surgical procedure:
Dr. Vinit Varu champions an endovascular repair, or EVAR. In this new, less invasive
technique, a catheter is inserted into the arteries through a small incision
in the groin. Under x-ray guidance, a vascular endograft is delivered
through the catheter and placed inside the aneurysm. This endografts fits
snugly into the normal artery above and below the aneurysm and so forms
a new pathway for the blood to flow thus excluding the aneurysm sac, which
then usually goes on to shrink. Patients go home the next day and frequently
are able to resume normal activity by one week. Most patients are suitable
for this minimally invasive technique, but all patients must undergo a
CT scan to ensure this technique is feasible.
Less commonly an open surgical repair is needed.
AAA before repair
Endovascular aneurysm repair (EVAR)
Successful exclusion of AAA following EVAR
Follow up CT scan showing successful repair