What Is an Aneurysm?
An aneurysm (AN-u-rism) is a balloon-like bulge in
an artery. Arteries are blood vessels that carry oxygen-rich blood from your
heart to your body.
Arteries have thick walls to withstand normal blood
pressure. However, certain medical problems, genetic conditions, and trauma can
damage or injure artery walls. The force of blood pushing against the weakened
or injured walls can cause an aneurysm.
An aneurysm can grow large and burst (rupture) or
cause a dissection. Rupture causes dangerous bleeding inside the body. A
dissection is a split in one or more layers of the artery wall. The split
causes bleeding into and along the layers of the artery wall.
Both conditions are often fatal.
Overview
Most aneurysms occur in the aortathe main
artery that carries blood from the heart to the rest of the body. The aorta
goes through the chest and abdomen.
An aneurysm that occurs in the part of the aorta
that's in the chest is called a thoracic (tho-RAS-ik) aortic aneurysm. An
aneurysm that occurs in the part of the aorta that's in the abdomen is called
an abdominal aortic aneurysm.
Aneurysms also can occur in other arteries, but
these types of aneurysm are less common. This article will focus on aortic
aneurysms.
About 14,000 Americans die each year from aortic
aneurysms. Most of the deaths result from rupture or dissection.
Early diagnosis and medical treatment can help
prevent many cases of rupture and dissection. However, aneurysms can develop
and become large before causing any symptoms. Thus, people who are at high risk
for aneurysms can benefit from early, routine screening.
Outlook
When found in time, aortic aneurysms often can be
successfully treated with medicines or surgery. Medicines may be given to lower
blood pressure, relax blood vessels, and reduce the risk of rupture.
Large aortic aneurysms often can be repaired with
surgery. During surgery, the weak or damaged portion of the aorta is replaced
or reinforced.
Types of Aneurysm
Aortic Aneurysms
The two types of aortic aneurysm are abdominal
aortic aneurysm (AAA) and thoracic aortic aneurysm (TAA).
Aortic Aneurysms
Figure A shows a normal aorta.
Figure B shows a thoracic aortic aneurysm (which is located behind the heart).
Figure C shows an abdominal aortic aneurysm located below the arteries that
supply blood to the kidneys.
Abdominal Aortic Aneurysms
An aneurysm that occurs in the part of the aorta
that's located in the abdomen is called an abdominal aortic aneurysm. AAAs
account for 3 in 4 aortic aneurysms. They're found more often now than in the
past because of computed tomography (to-MOG-rah-fee), or CT, scans done for
other medical problems.
Small AAAs rarely rupture. However, an AAA can grow
very large without causing symptoms. Thus, routine checkups and treatment for
an AAA are important to prevent growth and rupture.
Thoracic Aortic Aneurysms
An aneurysm that occurs in the part of the aorta
that's located in the chest and above the diaphragm is called a thoracic aortic
aneurysm. TAAs account for 1 in 4 aortic aneurysms.
TAAs don't always cause symptoms, even when they're
large. Only half of all people who have TAAs notice any symptoms. TAAs are
found more often now than in the past because of
chest
CT scans done for other medical problems.
With a common type of TAA, the walls of the aorta
weaken, and a section close to the heart enlarges. As a result, the valve
between the heart and the aorta can't close properly. This allows blood to leak
back into the heart.
A less common type of TAA can develop in the upper
back, away from the heart. A TAA in this location may result from an injury to
the chest, such as from a car crash.
Other Types of Aneurysms
Brain Aneurysms
When an aneurysm occurs in an artery in the brain,
it's called a
cerebral (seh-RE-bral or SER-eh-bral) aneurysm or brain
aneurysm. Brain aneurysms also are sometimes called berry aneurysms because
they're often the size of a small berry.
Brain Aneurysm
The illustration shows a typical
location of a brain (berry) aneurysm in the arteries supplying blood to the
brain. The inset image shows a closeup view of the sac-like aneurysm.
Most brain aneurysms cause no symptoms until they
become large, begin to leak blood, or rupture. A ruptured brain aneurysm causes
a
stroke.
Peripheral Aneurysms
Aneurysms that occur in arteries other than the
aorta and the brain arteries are called peripheral aneurysms. Common locations
for peripheral aneurysms include the popliteal (pop-li-TE-al), femoral
(FEM-o-ral), and carotid (ka-ROT-id) arteries.
The popliteal arteries run down the back of the
thighs, behind the knees. The femoral arteries are the main arteries in the
groin. The carotid arteries are the two main arteries on each side of your
neck.
Peripheral aneurysms arent as likely to
rupture or dissect as aortic aneurysms. However, blood clots can form in
peripheral aneurysms. If a blood clot breaks away from the aneurysm, it can
block blood flow through the artery.
If a peripheral aneurysm is large, it can press on a
nearby nerve or vein and cause pain, numbness, or swelling.
Other Names for Aneurysm
- Abdominal aortic aneurysm
- Aortic aneurysm
- Berry aneurysm
- Brain aneurysm
- Cerebral aneurysm
- Peripheral aneurysm
- Thoracic aortic aneurysm
What Causes an Aneurysm?
The force of blood pushing against the walls of an
artery combined with damage or injury to the arterys walls can cause an
aneurysm.
A number of factors can damage and weaken the walls
of the aorta and cause aortic aneurysms.
Aging, smoking,
high
blood pressure, and
atherosclerosis
(ath-er-o-skler-O-sis) are all factors that can damage or weaken the walls of
the aorta. Atherosclerosis is the hardening and narrowing of the arteries due
to the buildup of a fatty material called plaque (plak).
Rarely, infections, such as untreated syphilis (a
sexually transmitted infection), can cause aortic aneurysms. Aortic aneurysms
also can occur as a result of diseases that inflame the blood vessels, such as
vasculitis
(vas-kyu-LI-tis).
Family history also may play a role in causing
aortic aneurysms.
In addition to the factors above, certain genetic
conditions may cause thoracic aortic aneurysms (TAAs). Examples include
Marfan
syndrome, Loeys-Dietz syndrome, and
Ehlers-Danlos syndrome (the vascular type).
These conditions can weaken the bodys
connective tissues and damage the aorta. People who have these conditions tend
to develop aneurysms at a younger age and are at higher risk for rupture or
dissection.
Trauma, such as a car accident, also can damage the
aorta walls and lead to TAAs.
Researchers continue to look for other causes of
aortic aneurysms. For example, theyre looking for genetic mutations that
may contribute to or cause aneurysms.
Who Is At Risk for an Aneurysm?
Certain factors put you at higher risk for an aortic
aneurysm. These include:
- Male gender. Men are more likely than women to
have abdominal aortic aneurysms (AAAs)the most common type of
aneurysm.
- Age. The risk for AAAs increases as you get
older. These aneurysms are more likely to occur in people who are 65 or
older.
- Smoking. Smoking can damage and weaken the walls
of the aorta.
- Family history of aortic aneurysm. People who
have family histories of aortic aneurysm are at higher risk of having one, and
they may have aneurysms before the age of 65.
- Certain diseases and conditions that weaken the
walls of the aorta. For more information, see "What
Causes an Aneurysm?"
Car accidents or trauma also can injure the arteries
and increase your risk for an aneurysm.
If you have any of these risk factors, talk with
your doctor about whether you need to be screened for aneurysms.
What Are the Signs and Symptoms of an
Aneurysm?
The signs and symptoms of an aortic aneurysm depend
on the type of aneurysm, its location, and whether it has ruptured or is
affecting other parts of the body.
Aneurysms can develop and grow for years without
causing any signs or symptoms. They often don't cause signs or symptoms until
they rupture, grow large enough to press on nearby parts of the body, or block
blood flow.
Abdominal Aortic Aneurysms
Most abdominal aortic aneurysms (AAAs) develop
slowly over years. They often don't have signs or symptoms unless they rupture.
If you have an AAA, your doctor may feel a throbbing mass while checking your
abdomen.
When symptoms are present, they can include:
- A throbbing feeling in the abdomen
- Deep pain in your back or the side of your
abdomen
- Steady, gnawing pain in your abdomen that lasts
for hours or days
If an AAA ruptures, symptoms can include sudden,
severe pain in your lower abdomen and back; nausea (feeling sick to your
stomach) and vomiting; clammy, sweaty skin; lightheadedness; and a rapid heart
rate when standing up.
Internal bleeding from a ruptured AAA can send you
into shock. This is a life-threatening situation that requires emergency
treatment.
Thoracic Aortic Aneurysms
A thoracic aortic aneurysm (TAA) may not cause
symptoms until it dissects or grows large. Then, symptoms may include:
- Pain in your jaw, neck, back, or chest
- Coughing, hoarseness, or trouble breathing or
swallowing
A dissection is a split in one or more layers of the
artery wall. The split causes bleeding into and along the layers of the artery
wall.
If a TAA ruptures or dissects, you may feel sudden,
severe pain starting in your upper back and moving down into your abdomen. You
may have pain in your chest and arms, and you can quickly go into shock. Shock
is a life-threatening condition in which the bodys organs dont get
enough blood flow.
If you have any symptoms of TAA or aortic
dissection, call 911. If left untreated, these conditions may lead
to organ damage or death.
How Is an Aneurysm Diagnosed?
If you have aortic aneurysm, but no symptoms, your
doctor may find it by chance during a routine physical exam. More often,
doctors find aneurysms during tests done for other reasons, such as chest or
abdominal pain.
If you have an abdominal aortic aneurysm (AAA), your
doctor may feel a throbbing mass in your abdomen. A rapidly growing aneurysm
about to rupture can be tender and very painful when pressed. If you're
overweight
or obese, it may be hard for your doctor to feel even a large AAA.
If you have an AAA, your doctor may hear rushing
blood flow instead of the normal whooshing sound when listening to your abdomen
with a stethoscope.
Specialists Involved
Your primary care doctor may refer you to a
cardiothoracic or vascular surgeon for diagnosis and treatment of an aortic
aneurysm.
A cardiothoracic surgeon performs surgery on the
heart, lungs, and other organs and structures in the chest, including the
aorta. A vascular surgeon performs surgery on the aorta and other blood
vessels, except those of the heart and brain.
Diagnostic Tests and Procedures
To diagnose and evaluate an aneurysm, your doctor
may recommend one or more of the following tests.
Ultrasound
This simple, painless test uses sound waves to
create pictures of the structures inside your body. Ultrasound shows the size
of an aneurysm, if one is found.
Computed Tomography Scan
A computed tomography (CT) scan is a painless test
that uses x rays to take clear, detailed pictures of your internal organs.
During the test, your doctor will inject a special
dye into a vein in your arm. This dye highlights the aorta on the CT scan
images.
Your doctor may recommend this test if he or she
thinks you have an AAA or a thoracic aortic aneurysm (TAA). A CT scan can show
the size and shape of an aneurysm. This test provides more detailed images than
an ultrasound.
Magnetic Resonance Imaging
Magnetic resonance imaging (MRI) uses magnets and
radio waves to create images of the organs and structures in your body. This
test is very accurate at detecting aneurysms and pinpointing their size and
exact location.
Angiography
Angiography (an-jee-OG-ra-fee) uses a special dye
injected into the bloodstream to highlight the insides of arteries on x-ray
pictures. An angiogram shows the amount of damage and blockage in blood
vessels.
An angiogram of the aorta is called an aortogram. An
aortogram may show the location and size of an aortic aneurysm.
How Is an Aneurysm Treated?
Aortic aneurysms are treated with medicines and
surgery. A small aneurysm that's found early and isn't causing symptoms may not
need treatment. Other aneurysms need to be treated.
The goals of treatment are to:
- Prevent the aneurysm from growing
- Prevent or reverse damage to other body
structures
- Prevent or treat a rupture or dissection
- Allow you to continue to do your normal daily
activities
Treatment for aortic aneurysms is based on the size
of the aneurysm. Your doctor may recommend routine testing to make sure an
aneurysm isn't getting bigger. This method usually is used for aneurysms that
are smaller than 5 centimeters (about 2 inches) across.
How often you need testing (for example, every few
months or every year) will be based on the size of the aneurysm and how fast
it's growing. The larger it is and the faster it's growing, the more often you
may need to be checked.
Medicines
If you have an aortic aneurysm, your doctor may
prescribe medicines before surgery or instead of surgery. Medicines are used to
lower blood pressure, relax blood vessels, and reduce the risk of rupture. Beta
blockers and calcium channel blockers are the medicines most commonly used.
Surgery
Your doctor may recommend surgery if your aneurysm
is growing quickly or if it reaches a size linked with an increased risk of
rupture or dissection.
The two main types of surgery to repair aortic
aneurysms are open abdominal or open chest repair and endovascular repair.
Open Abdominal or Open Chest Repair
The standard and most common type of surgery for
aortic aneurysms is open abdominal or open chest repair. It involves a major
incision (cut) in the abdomen or chest. General anesthesia is used for this
procedurethat is, you will be temporarily put to sleep so you don't feel
pain during the surgery.
The aneurysm is removed, and the section of aorta is
replaced with a graft made of material such as Dacron® or
Teflon.® The surgery takes 3 to 6 hours, and you will remain in
the hospital for 5 to 8 days.
It often takes a month to recover from open
abdominal or open chest surgery and return to full activity. Most patients make
a full recovery.
Endovascular Repair
In endovascular repair, the aneurysm isn't removed.
Instead, a graft is inserted into the aorta to strengthen it. This type of
surgery is done using catheters (tubes) inserted into the arteries; it doesn't
require surgically opening the chest or abdomen.
The surgeon first inserts a catheter into an artery
in the groin (upper thigh) and threads it to the aneurysm. Then, using an x ray
to see the artery, the surgeon threads the graft (also called a stent graft)
into the aorta to the aneurysm.
The graft is then expanded inside the aorta and
fastened in place to form a stable channel for blood flow. The graft reinforces
the weakened section of the aorta to prevent the aneurysm from rupturing.
Endovascular Repair
The illustration shows the placement
of an endovascular stent graft in an aortic aneurysm. In figure A, a catheter
is inserted into an artery in the groin (upper thigh). The catheter is threaded
to the abdominal aorta, and the stent graft is released from the catheter. In
figure B, the stent graft allows blood to flow through the aneurysm.
Endovascular repair reduces recovery time to a few
days and greatly reduces time in the hospital. However, doctors cant
repair all aortic aneurysms with this procedure. The location or size of the
aneurysm may prevent a stent graft from being safely or reliably placed inside
the aneurysm.
How Can an Aneurysm Be Prevented?
The best way to prevent an aortic aneurysm is to
avoid the factors that put you at higher risk for one. You cant control
all of the risk factors for aortic aneurysm, but lifestyle changes can help you
reduce some risks.
Lifestyle changes include quitting smoking and
controlling conditions such as
high
blood pressure and
high
blood cholesterol.
Talk to your doctor about programs and products that
can help you quit smoking. Also try to avoid secondhand smoke.
Follow a healthy diet and be as physically active as
you can. A healthy diet includes a variety of fruits, vegetables, and whole
grains.
It also includes lean meats, poultry, fish, beans,
and fat-free or low-fat milk or milk products. A healthy diet is low in
saturated fat, trans fat, cholesterol, sodium (salt), and added
sugar.
For more information on following a healthy diet,
see the National Heart, Lung, and Blood Institutes (NHLBIs)
Aim for a
Healthy Weight Web site,
"Your
Guide to a Healthy Heart," and
"Your
Guide to Lowering Your Blood Pressure With DASH." All of these resources
include general information about healthy eating.
Talk to your doctor about the amounts and types of
physical activity that are safe for you. For more information on physical
activity, see the Diseases and Conditions Index Physical Activity and Your
Heart article and NHLBIs
"Your
Guide to Physical Activity and Your Heart."
Follow your treatment plans for any other medical
conditions you have. Take all of your medicines as prescribed.
Living With an Aneurysm
If you have an aortic aneurysm, its important
to follow your treatment plan and have ongoing medical care. Early diagnosis
and treatment help prevent many cases of rupture and dissection.
Aneurysms can develop and become large before
causing any symptoms. Thus, people who are at high risk for aneurysms may need
routine screening to find and monitor an aneurysm.
If you have a small aneurysm that isnt causing
pain, you may not need treatment. However, you may need routine tests to make
sure the aneurysm isnt getting bigger.
Your doctor may prescribe medicines to treat your
aneurysm. Medicines can lower your blood pressure, relax your blood vessels,
and reduce the risk of rupture. Take all of your medicines exactly as your
doctor prescribes.
Key Points
- An aneurysm is a balloon-like bulge in an artery.
Arteries are blood vessels that carry oxygen-rich blood from your heart to your
body.
- Arteries have thick walls to withstand normal
blood pressure. However, certain medical problems, genetic conditions, and
trauma can damage or injure artery walls. The force of blood pushing against
the weakened or injured walls can cause an aneurysm.
- An aneurysm can grow large and burst (rupture) or
cause a dissection. Rupture causes dangerous bleeding inside the body. A
dissection is a split in one or more layers of the artery wall. The split
causes bleeding into and along the layers of the artery wall. Both conditions
are often fatal.
- Most aneurysms occur in the aortathe main
artery that carries blood from the heart to the rest of the body. The aorta
goes through the chest and abdomen.
- An aneurysm that occurs in the part of the aorta
that's in the chest is called a thoracic aortic aneurysm (TAA). An aneurysm
that occurs in the part of the aorta in the abdomen is called an abdominal
aortic aneurysm (AAA). Aneurysms also can occur in other arteries, but these
types of aneurysm are less common.
- A number of factors can damage and weaken the
walls of the aorta and cause aortic aneurysms. Examples include aging, smoking,
high
blood pressure,
atherosclerosis,
infections, certain genetic conditions, and trauma. Family history also may
play a role in causing aortic aneurysms.
- The signs and symptoms of an aortic aneurysm
depend on the type of aneurysm, its location, and whether it has ruptured or is
affecting other parts of the body. Aneurysms can develop and grow for years
without causing signs or symptoms.
- Your doctor may find an aortic aneurysm by chance
during a routine physical exam. More often, doctors find aneurysms during tests
done for other reasons, such as chest or abdominal pain. To diagnose and
evaluate an aneurysm, your doctor may recommend one or more tests.
- Aortic aneurysms are treated with medicines and
surgery. A small aneurysm that's found early and isn't causing symptoms may not
need treatment. Every aneurysm should be evaluated.
- Your doctor may prescribe medicines before
surgery or instead of surgery. He or she may recommend surgery if your aneurysm
is growing quickly or if it reaches a size linked with an increased risk of
rupture or dissection.
- The best way to prevent an aneurysm is to avoid
the factors that put you at higher risk for one. You can't control all of the
risk factors for aneurysm, but lifestyle changes can help you reduce your
risks. Examples of lifestyle changes include following a healthy diet, doing
physical activity, not smoking, and treating other medical conditions such as
high blood pressure and
high
blood cholesterol.
- If you have an aortic aneurysm, it's important to
follow your treatment plan and have ongoing medical care. Early diagnosis and
treatment help prevent many cases of rupture and dissection.
Links to Other Information About Aneurysm
Non-NHLBI Resources
Clinical Trials
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