What are the causes of aortic
aneurysms or dissection?
Well with respect to dissection, atherosclerosis
is a very common cause. Excessive alcohol
can lead to high blood pressure which puts
greater stress on the aortic wall and therefore
that combination of smoking, high alcohol
intake, and high blood pressure can often
lead either to an aortic dilated aneurysm
or an aortic dissection.
There are genetic influences. It's well known
now that certain genetic types and in fact
the genes have been identified in certain
families that in fact lead to a very high
risk of dissection or aortic aneurysm. And
congenital heart lesions such as coarctation
of the aorta or a bicuspid aortic valve also
markedly increase the risks for an aortic
aneurysm because the wall of the aorta is
abnormally formed often in these two entities.
Trauma can also cause an aneurysm by partly
tearing the aorta for example someone in the
car accident, the sudden deceleration might
cause a tear in the aorta that could lead
to dissection or to a later dilated aneurysm.
Occasionally an infection will do this. Infected
aneurysms are very nasty. They do require
surgery to remove the entire infected part
and then again of course always involved in
these processes that lead to aneurysms or
dissection is atherosclerosis because of the
way that it makes for abnormal flow characteristics
and abnormal structure of the aortic wall.
About 9% of people older than 65 in the United
States will have an aneurysm, usually an abdominal
aortic aneurysm, and it leads to about 15000
deaths in United States per year from hemorrhage
when the aneurysm ruptures or bursts. The
symptoms depend on the location of the aneurysm.
So if the aneurysm is in the thoracic aorta,
the discomfort may be on the anterior part
of the chest, here substernally, it may be
in the back or even in the neck. When the
aortic aneurysm is tearing or rupturing in
the abdomen, the discomfort may be in the
anterior abdomen or in the back of the aneurysm
depending often on where the tear is occurring
and where the blood is starting to leak out.
With a thoracic aortic aneurysm, patients
may actually become hoarse because the recurrent
laryngeal nerve winds around the aortic arch
and they may be stretched by an aneurysm,
so chronic hoarseness could be a symptom of
a thoracic aortic aneurysm particularly in
somebody who is at risk. Somebody who you know
could be atherosclerotic, who is hypertensive,
who is a smoker. And finally when aneurysms
become very large in the chest, the thoracic
aneurysms, patients may have difficulty swallowing
because the aneurysm is pressing against the
esophagus which lies just in front of it and
that can cause problems in swallowing because
the esophagus is constricted by the pressure
from the aneurysm.