What Is an Aneurysm?
An aneurysm (AN-u-rism) is an abnormal bulge or
ballooning in the wall of an artery. Arteries are blood vessels
that carry oxygen-rich blood from the heart to other parts of the body. An
aneurysm that grows and becomes large enough can burst, causing dangerous,
often fatal, bleeding inside the body.
Most aneurysms occur in the aorta. The aorta is the
main artery that carries blood from the heart to the rest of the body. The
aorta comes out from the left ventricle (VEN-trih-kul) of the heart and travels
through the chest and abdomen. An aneurysm that occurs in the aorta in the
chest is called a thoracic (tho-RAS-ik) aortic aneurysm. An aneurysm that
occurs in the aorta in the abdomen is called an abdominal aortic aneurysm.
Aneurysms also can occur in arteries in the brain,
heart, intestine, neck, spleen, back of the knees and thighs, and in other
parts of the body. If an aneurysm in the brain bursts, it causes a
stroke.
About 15,000 Americans die each year from ruptured
aortic aneurysms. Ruptured aortic aneurysm is the 10th leading cause of death
in men over age 50 in the United States.
Many cases of ruptured aneurysm can be prevented
with early diagnosis and medical treatment. Because aneurysms can develop and
become large before causing any symptoms, it is important to look for them in
people who are at the highest risk. Experts recommend that men who are 65 to 75
years old and have ever smoked (at least 100 cigarettes in their lifetime)
should be checked for abdominal aortic aneurysms.
When found in time, aneurysms can usually be treated
successfully with medicines or surgery. If an aortic aneurysm is found, the
doctor may prescribe medicine to reduce the heart rate and blood pressure. This
can reduce the risk of rupture.
Large aortic aneurysms, if found in time, can often
be repaired with surgery to replace the diseased portion of the aorta. The
outlook is usually excellent.
Types of Aneurysm
Types of aneurysm include aortic aneurysms, cerebral
aneurysms, and peripheral aneurysms.
Aortic Aneurysm
Most aneurysms occur in the aorta. The aorta is the
main artery that carries blood from the heart to the rest of the body. The
aorta comes out from the left ventricle of the heart and travels through the
chest and abdomen. The two types of aortic aneurysm are thoracic aortic
aneurysm (TAA) and abdominal aortic aneurysm (AAA).
Thoracic Aortic Aneurysm
An aortic aneurysm that occurs in the part of the
aorta running through the thorax (chest) is a thoracic aortic aneurysm. One in
four aortic aneurysms is a TAA.
Most TAAs do not produce symptoms, even when they
are large. Only half of all people with TAAs notice any symptoms. TAAs are
identified more often now than in the past because of chest
computed tomography (CT) scans performed for other medical
problems.
In a common type of TAA, the walls of the aorta
become weak and a section nearest to the heart enlarges. Then the valve between
the heart and the aorta cannot close properly and blood leaks backward into the
heart. Less commonly, a TAA can develop in the upper back away from the heart.
A TAA in this location can result from and injury to the chest such as from an
auto crash.
Abdominal Aortic Aneurysm
An aortic aneurysm that occurs in the part of the
aorta running through the abdomen is an abdominal aortic aneurysm. Three in
four aortic aneurysms are AAAs.
An AAA can grow very large without producing
symptoms. About 1 in 5 AAAs rupture.
Figure A shows a normal aorta.
Figure B shows a thoracic aortic aneurysm located behind the heart. Figure C
shows an abdominal aortic aneurysm located below the arteries that supply the
kidneys.
Cerebral Aneurysm
Aneurysms that occur in an artery in the brain are
called cerebral aneurysms. They are sometimes called berry aneurysms because
they are often the size of a small berry. Most cerebral aneurysms produce no
symptoms until they become large, begin to leak blood, or rupture.
The illustration shows a typical
location of a cerebral (berry) aneurysm in the arteries supplying blood to the
brain. The inset image shows a closeup of the sac-like aneurysm.
A ruptured cerebral aneurysm causes a
stroke. Signs and symptoms can include a sudden, extremely
severe headache, nausea, vomiting, stiff neck, sudden weakness in an area of
the body, sudden difficulty speaking, and even loss of consciousness, coma, or
death. The danger of a cerebral aneurysm depends on its size and location in
the brain, whether it leaks or ruptures, and the persons age and overall
health.
Peripheral Aneurysm
Aneurysms that occur in arteries other than the
aorta (and not in the brain) are called peripheral aneurysms. Common locations
for peripheral aneurysms include the artery that runs down the back of the
thigh behind the knee (popliteal artery), the main artery in the groin (femoral
artery), and the main artery in the neck (carotid artery).
Peripheral aneurysms are not as likely to rupture as
aortic aneurysms, but 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
- Aortic aneurysm
- Abdominal aortic aneurysm, or AAA
- Thoracic aortic aneurysm, or TAA
- Cerebral aneurysm
- Peripheral aneurysm
What Causes an Aneurysm?
An aneurysm can result from
atherosclerosis
(hardening and narrowing of the inside of arteries). As atherosclerosis
develops, the artery walls become thick and damaged and lose their normal inner
lining. This damaged area of artery can stretch or balloon from the
pressure of blood flow inside the artery, resulting in an aneurysm.
An aneurysm also can develop from constant
high
blood pressure inside an artery.
A thoracic aortic aneurysm can result from an injury
to the chest (for example, an injury that occurs from an auto crash). Certain
medical conditions, such as Marfan
syndrome, that weaken the bodys connective tissues, also can cause
aneurysms.
In rare cases, infections such as untreated syphilis
(a sexually transmitted infection) can cause aortic aneurysms. Aortic aneurysms
also can occur as a result of diseases that cause inflammation of blood
vessels, such as
vasculitis.
Who Is At Risk for an Aneurysm?
Populations Affected
Men are 5 to 10 times more likely than women to have
an abdominal aortic aneurysm (AAA)the most common type of aneurysm.
The risk of AAA increases as you get older, and it
is more likely to occur in people between the ages of 60 to 80. A peripheral
aneurysm also is more likely to affect people ages 60 to 80. Cerebral (brain)
aneurysms, though rare, are more likely to occur in people ages 35 to 60.
Risk Factors
Factors that increase your risk for aneurysm
include:
- Atherosclerosis,
a buildup of fatty deposits in the arteries.
- Smoking. You are eight times more likely to
develop an aneurysm if you smoke.
- Overweight or obesity.
- A family history of aortic aneurysm, heart
disease, or other diseases of the arteries.
- Certain diseases that can weaken the wall of the
aorta, such as:
- Marfan
syndrome (an inherited disease in which tissues dont develop
normally)
- Untreated syphilis (a very rare cause
today)
- Tuberculosis (also a very rare cause
today)
- Trauma such as a blow to the chest in a car
accident.
- Severe and persistent
high
blood pressure between the ages of 35 and 60. This increases the risk for a
cerebral aneurysm.
- Use of stimulant drugs such as cocaine.
What Are the Signs and Symptoms of an
Aneurysm?
The signs and symptoms of an aneurysm depend on its
type, location, and whether it has ruptured or is interfering with other
structures in the body. Aneurysms can develop and grow for years without
causing any signs or symptoms. It is often not until an aneurysm ruptures or
grows large enough to press on nearby parts of the body or block blood flow
that it produces any signs or symptoms.
Abdominal Aortic Aneurysm
Most abdominal aortic aneurysms (AAAs) develop
slowly over years and have no signs or symptoms until (or if) they rupture.
Sometimes, a doctor can feel a pulsating mass while examining a patient's
abdomen. When symptoms are present, they can include:
- Deep penetrating pain in your back or the side of
your abdomen
- Steady gnawing pain in your abdomen that lasts
for hours or days at a time
- Coldness, numbness, or tingling in your feet due
to blocked blood flow in your legs
If an AAA ruptures, symptoms can include sudden,
severe pain in your lower abdomen and back; nausea 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. Shock is a
life-threatening condition in which the organs of the body do not get enough
blood flow.
Thoracic Aortic Aneurysm
A thoracic (chest) aortic aneurysm may have no
symptoms until the aneurysm begins to leak or grow. Signs or symptoms may
include:
- Pain in your jaw, neck, upper back (or other part
of your back), or chest
- Coughing, hoarseness, or trouble breathing
Cerebral Aneurysm
If a cerebral (brain) aneurysm presses on nerves in
your brain, it can cause signs and symptoms. These can include:
- A droopy eyelid
- Double vision or other changes in vision
- Pain above or behind the eye
- A dilated pupil
- Numbness or weakness on one side of the face or
body
If a cerebral aneurysm ruptures, symptoms can
include a sudden, severe headache, nausea and vomiting, stiff neck, loss of
consciousness, and signs of a
stroke. Signs of a stroke are similar to those listed above
for cerebral aneurysm, but they usually come on suddenly and are more severe.
Any of these symptoms require immediate medical attention.
Peripheral Aneurysm
Signs and symptoms of peripheral aneurysm may
include:
- A pulsating lump that can be felt in your neck,
arm, or leg
- Leg or arm pain, or cramping with exercise
- Painful sores on toes or fingers
- Gangrene (tissue death) from severely blocked
blood flow in your limbs
An aneurysm in the popliteal artery (behind the
knee) can compress nerves and cause pain, weakness, and numbness in your knee
and leg.
Blood clots can form in peripheral aneurysms. If a
clot breaks loose and travels through the bloodstream, it can lodge in your
arm, leg, or brain and block the artery. An aneurysm in your neck can block the
artery to the brain and cause a stroke.
How Is an Aneurysm Diagnosed?
An aneurysm may be found by chance during a routine
physical exam. More often, an aneurysm is found by chance during an
x ray,
ultrasound, or
computed tomography (CT) scan performed for another reason,
such as chest or abdominal pain.
If you have an abdominal aortic aneurysm (AAA), the
doctor may feel a pulsating mass in your abdomen. A rapidly growing aneurysm
about to rupture can be tender and very painful when pressed. If you are
overweight or obese, it may be difficult for your doctor to feel even a large
abdominal aneurysm.
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
You may be referred to a cardiothoracic surgeon,
vascular surgeon, or neurosurgeon for diagnosis and treatment of an 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 abdominal aorta and on the peripheral arteries. A neurosurgeon
performs surgery on the brain, including the arteries in the head, and on the
spine and nerves.
Diagnostic Tests and Procedures
To diagnose and evaluate an aneurysm, one or more of
the following tests or procedures may be performed:
- Chest x ray. A chest x ray provides a picture of
the organs and structures inside the chest, including the heart, lungs, and
blood vessels.
- Ultrasound. This simple and painless test uses
sound waves to create a picture of the inside of the body. It shows the size of
an aneurysm, if one is detected. The ultrasound scan may be repeated every few
months to see how quickly an aneurysm is growing.
- CT scan. A CT scan provides computer-generated,
x-ray images of the internal organs. A CT scan may be performed if the doctor
suspects a TAA or AAA. A liquid dye that can be seen on an x ray is injected
into an arm vein to outline the aorta or artery on the CT scan. The CT scan
images can be used to determine the size and shape of an abdominal aneurysm
more accurately than an ultrasound.
- MRI. MRI uses magnets and radio waves to create
images of the inside of the body. It is very accurate in detecting aneurysms
and determining their size and exact location.
- Angiography. Angiography also uses a special dye injected into
the blood stream to make the insides of arteries show up on x-ray pictures. An
angiogram shows the amount of damage and blockage in blood vessels.
- Aortogram. An aortogram is an angiogram of the aorta. It may
show the location and size of an aortic aneurysm, and the arteries of the aorta
that are involved.
How Is an Aneurysm Treated?
Goals of Treatment
Some aneurysms, mainly small ones that are not
causing pain, can be treated with watchful waiting. Others need to
be treated to prevent growth and complications. The goals of treatment are to
prevent the aneurysm from growing, prevent or reverse damage to other body
structures, prevent or treat a rupture, and to allow you to continue to
participate in normal daily activities.
Treatment Options
Medicine and surgery are the two types of treatment
for an aneurysm. Medicines may be prescribed before surgery or instead of
surgery. Medicines are used to reduce pressure, relax blood vessels, and reduce
the risk of rupture. Beta blockers and calcium channel blockers are the
medicines most commonly used.
Surgery may be recommended if an aneurysm is large
and likely to rupture.
Treatment by Type of Aneurysm
Aortic Aneurysm
Experts recommend that men who have ever smoked (at
least 100 cigarettes in their lifetime) and are between the ages of 65 and 75
should have an
ultrasound screening to check for abdominal aortic
aneurysms.
Treatment recommendations for aortic aneurysms are
based on the size of the aneurysm. Small aneurysms found early can be treated
with watchful waiting.
- If the diameter of the aorta is smallless
than 3 centimeters (cm)and there are no symptoms, watchful
waiting and a followup screening in 5 to 10 years may be all that is
needed, as determined by the doctor.
- If the aorta is between 3 and 4 cm in diameter,
the patient should return to the doctor every year for an ultrasound to see if
the aneurysm has grown.
- If the aorta is between 4 and 4.5 cm, testing
should be repeated every 6 months.
- If the aorta is larger than 5 cm (2 inches around
or about the size of a lemon) or growing more than 1 cm per year, surgery
should be considered as soon as possible.
Two main types of surgery to repair aortic aneurysms
are open abdominal or open chest repair and endovascular repair.
The traditional and most common type of surgery for
aortic aneurysms is open abdominal or open chest repair. It involves a major
incision in the abdomen or chest. General anesthesia is needed with this
procedure.
The aneurysm is removed and the section of aorta is
replaced with an artificial graft made of material such as Dacron® or
Teflon®. The surgery takes 3 to 6 hours, and the patient remains 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. Open abdominal and chest
surgeries have been performed for 50 years. More than 90 percent of patients
make a full recovery.
In endovascular repair, the aneurysm is not removed,
but a graft is inserted into the aorta to strengthen it. This type of surgery
is performed through catheters (tubes) inserted into the arteries; it does not
require surgically opening the chest or abdomen.
To perform endovascular repair, the doctor first
inserts a catheter into an artery in the groin (upper thigh) and threads it up
to the area of the aneurysm. Then, watching on
x ray, 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.
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). It is then threaded up
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 surgery reduces recovery time to
a few days and greatly reduces time in the hospital. The procedure has been
used since 1999. Not all aortic aneurysms can be repaired with this procedure.
The exact location or size of the aneurysm may prevent the stent graft from
being safely or reliably positioned inside the aneurysm.
Cerebral Aneurysm
Treatment for cerebral (brain) aneurysms depends on
the size and location of the aneurysm, whether it is infected, and whether it
has ruptured. A small cerebral aneurysm that hasnt burst may not need
treatment. A large cerebral aneurysm may press against brain tissue, causing a
severe headache or impaired vision, and is likely to burst. If the aneurysm
ruptures, there will be bleeding into the brain which will cause a
stroke. If a cerebral aneurysm becomes infected, it requires
immediate medical treatment. Treatment of many cerebral aneurysms, especially
large or growing ones, involves surgery, which can be risky depending on the
location of the aneurysm.
Peripheral Aneurysm
Most peripheral aneurysms have no symptoms,
especially if they are small. They seldom rupture.
Treatment of peripheral aneurysms depends on the
presence of symptoms, the location of the aneurysm, and whether the blood flow
through the artery is blocked. Blood clots can form in a peripheral aneurysm,
break loose, and block the artery.
An aneurysm in the back of the knee that is larger
than 1 inch in diameter usually requires surgery. An aneurysm in the thigh also
is usually repaired with surgery.
How Can an Aneurysm Be Prevented?
The best way to prevent an aneurysm is to avoid the
risk factors that increase the changes of developing one. To do this, you
can:
- Quit smoking.
- Eat a low-fat, low-cholesterol diet to reduce the
buildup of plaque in the arteries. Plaque is a fatty buildup that narrows the
arteries.
- Control
high
blood pressure (eating a low-salt diet helps).
- Control
high
cholesterol.
- Get regular physical activity.
Key Points
- An aneurysm is an abnormal bulge or
ballooning in the wall of an artery. Arteries are blood vessels
that carry oxygen-rich blood from the heart to other parts of the body.
- An aneurysm that grows and becomes large enough
can rupture, causing dangerous bleeding inside the body.
- Most aneurysms occur in the aorta. The aorta is
the main artery that carries blood from the heart to the rest of the body.
- Most aneurysms (3 out of 4) are found by chance
when a diagnostic test, such as
x ray or
ultrasound, is performed for a different reason.
- Many cases of ruptured aneurysm can be prevented
with early diagnosis and medical treatment.
- Because aneurysms can develop and become large
before causing any symptoms, it is important to look for them in people who are
at the highest risk. Ultrasound screening for abdominal aortic aneurysms is
recommended for men who have ever smoked and are between the ages of 65 and
75.
- Medicines and surgery are the two main treatments
for aneurysms. Medicines may be prescribed before surgery or instead of
surgery.
- To prevent an aneurysm and keep blood vessels
healthy, quit smoking, eat a low-fat, low-cholesterol diet, get regular
physical activity, and control
high
blood pressure and
high
cholesterol.
Links to Other Information About Aneurysm
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