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Answers to Frequently Asked Questions about Abdominal
Aortic Aneurysms, prepared by:
M. David Tilson, MD
Professor of Surgery
New York City
*Please see Section 11 for the most recent update, May 2004,
regarding Endovascular Repair*
1. What is an aneurysm?
An aneurysm is a dilation of a blood vessel (similar
to a balloon) that poses a risk to health from the
potential for rupture, clotting, or dissecting. Rupture
of an aneurysm in the brain causes stroke, and rupture of
an aneurysm in the abdomen causes shock. The abdominal
aortic aneurysm (AAA) is the most common, and the rest of
this discussion will focus on the AAA.
2. What causes aneurysms?
Several new theories have developed over the last 15
years. It appears that the disease probably requires a
basic genetic susceptibility that may be traceable to a
single major locus, probably an autosomal dominant
gene. The disease unequivocally runs in families. In
addition, there are probably other contributing causes,
such as smoking and high blood pressure.
3. Who is at greatest risk?
White men over age 55 are at the greatest risk. In
fact, aneurysms are among the top ten causes of death
among this group. By about age 80, over 5% of white males will have
developed an aneurysm. AAA's occur less frequently in
white women, and they are relatively uncommon in African
Americans of both sexes.
4. Why are aneurysms so dangerous?
AAA's cause many deaths because they are usually
silent until a medical emergency occurs. One author has
referred to an AAA as a "U-boat" in the belly, because
they are silent, deep, deadly, and detectable by sound waves.
5. How can I find out if I have one?
If you are thin and have a moderately large-sized
AAA, you or your doctor may be able to feel it below your
rib cage. Many are incidentally discovered as a result
of medical imaging for other conditions, by ultrasound
exams, CAT scans, MRI's, or even plain X©rays of the
abdomen. If you are over 55 and other members of your
family have had one or more AAA's, you should advise your
doctor and have an ultrasound. It is safe, fast and
6. If I have an aneurysm, what is the risk of death from
If rupture occurs, few survive. Among celebrities,
Roy Rogers survived a rupture, but he was the exception
and not the rule. Albert Einstein, Lucille Ball, and Conway
Twitty were not so fortunate. The best predictor of risk of
rupture is the size of the aneurysm. The diameter of a normal
aorta is about 2 centimeters (a little less than an inch).
Once a AAA has reached 5-6 centimeters in diameter, about the
size of an orange, the risk of rupture is very substantial, probably
about 50/50 over the next few years. Most vascular surgeons
would agree that a 5-6 cm aneurysm should be repaired, unless other
medical factors in a patient make the operation too risky. There
is less unanimity of opinion about smaller AAA's, since the risk of
rupture is much lower. Some surgeons are now recommending repair of
aneurysms over 3 centimeters, but others would advise watchful
waiting for AAA's that small. There is presently a controlled,
randomized, multi-center trial being carried out in the Veterans
Administration Hospitals to try to answer the question as to when
the size of the aneurysm indicates that the surgical risk for the
patient has become less than the risk from rupture.
7. What is "watchful waiting?"
Most vascular surgeons feel comfortable following
patients with small AAA's every six months with an
ultrasound examination. The average rate of growth of an
aneurysm is less than one-half of a centimeter per year,
and some grow much slower, remaining relatively stable
for fairly long periods of time. Others may enlarge
rapidly, and a "growth spurt" is a serious warning sign.
8. Is there anything one can do while "waiting"?
Giving up tobacco, making sure of reasonable blood
pressure control, and improving physical fitness with a
mild exercise program are all prudent. So far, no
medication has been proven in a prospective scientific
experiment to reduce the growth rate of AAA's in people,
although propranolol (a beta-blocker) has been shown to
reduce the incidence of ruptured aneurysms in turkeys and to
delay the growth of aneurysms in mice. Retrospective studies
at Yale and at the University of Vermont have suggested thatp
ropranolol might be beneficial in people, but proof will await a
prospective trial. Such a trial is now being planned by
surgeons at the University of Vermont.
9. What are the risks of surgical repair?
The risk of death from surgery is related to
hospital expertise and experience, the skill of the
surgeon, and the basic underlying health of the patient.
Mortality rates are frequently reported to be as low as
0 to 2% in academic medical centers with vascular
specialists and superior intensive care. Rates may be
higher in small community hospitals without dedicated
vascular specialists. Patients without any history
or signs of heart disease generally do very well,
because heart attack postoperatively is the leading cause
of surgical mortality. Patients with known coronary
artery disease should have a thorough cardiological
evaluation prior to surgery.
10. How long does it take to recover, and what is the likelihood of
returning to a normal life?
The average hospital stay is 7-10 days, and most
patients take about 6 weeks off before returning to work.
By that time, they have usually regained their sense of
well being, although some bounce back much faster. The
vast majority of patients are back on a normal survival
curve for life expectancy, consistent with their cohort
of persons of similar age and with similar underlying
health (e.g., heart condition, renal function, etc.). One
unfortunate complication, about which male patients should
be forewarned, is the possibility of sexual dysfunction.
If this occurs, it usually takes the form of "retrograde
ejaculation", not impotence. For more information, please
consult with your doctor.
11. I've heard of "minimally invasive surgery". Does
this work for AAA?
There has been recent progress toward this goal. An
"endovascular" repair (e.g., using tubes, stents, and
wires threaded up into the aneurysm from leg arteries)
was developed by a surgeon in Argentina and is presently
coming into use in the United States. This procedure is
presently considered to be in its developmental stages,
and it is offered only in selected centers.
[Addendum to this FAQ, April 30, 1995: Dr. Juan Perodi has
just published an account of the first 50 of these aneurysm
procedures, reviewed by mdt in the April Papers of the Month
section in the Aneurysm Information Project Home Page.]
[Addendum, May 2004: In the past decade, it is fair to say
that the endovascular approach has matured to the point
where many specialists presently consider it to be the
procedure "of choice". Please click on Aneurysm Surgery
back at the homepage for a link to Dr. Todd's website,
where there is a very informative discussion of the present
state of endovascular versus open repair.]
>For a quick link to this comparison, click
12. What can I do to help the Aneurysm Information Project
reach more people?
Good question. It's absolutely amazing that almost
as many people die from aneurysms as from diseases that get
tremendous amounts of public attention and awareness (like
AIDS and breast cancer). I guess because its primary
victims are aging Caucasian males, it doesn't have much sex
appeal. But just as early detection of breast cancer with
mammography can save life, so can early detection of AAA by
ultrasound. Advising family members over age 50-55 to have
an ultrasound (and letting your older friends know that
about 5% of men over 70 will be positive) should certainly
prevent unnecessary loss of life.
13. Is there anything I can do to help advance knowledge of
the causes and prevention of aneurysms through research?
Thanks for asking. While the NIH is spending almost
two billion $ / year on AIDS and hundreds of millions / year on
breast cancer, AAA's only got a few hundred thousand $. I am
presently keeping my research program alive thanks to the
generosity of friends of the Aneurysm Information Project. On
an average, it costs about $50-75,000 to do an experiment; and
my students and I hope to finish about 4 this year. That gives
you an idea about the scale of fund-raising I need to
accomplish to stay in the chase for the aneurysm susceptibility
One of my parent organizations, the St.Luke's/Roosevelt
Hospital Center is non-profit and tax-exempt, so that you may
make a fully tax-deductible gift to it, earmarked for the
Special Fund for Resident Research on Aneurysms (which is under
my authority). Friends of the Special Fund will get periodic
reports from me on the status of the research program; and
especially generous contributions will be acknowledged with
appreciation in the footnotes to our scientific papers.
Make check to SLR Hospital Center
Mail to M. D. Tilson, MD
SLR Hospital Center
1000 Tenth Avenue
New York, NY 10019