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Stents
What Are Stents?
A stent is a small mesh tube typically used to hold open passages in the
body, such
as weak or narrowed blood vessels. Stents are often used to treat
narrowing in the coronary arteries, which provide the heart with
oxygen-rich blood. Stents can also help to treat an aneurysm, which is a
bulge in the wall of an artery, as well as narrowed airways in the
lungs.
Stenting is a minimally invasive procedure, meaning it does not
require a large, open incision in the body and is not considered major
surgery. However, before
you get a stent, you may need certain tests or some medicines to
prepare for the procedure. Stents can be made of metal mesh, fabric,
silicone, or combinations of materials. Stents for coronary arteries are
usually made of metal mesh and sometimes covered with another material.
Fabric stents, or stent grafts, are used in larger arteries such as the
aorta. Stents used in the airways of the lungs are often made of
silicone.
After you receive a stent, and depending on its location in the
body, you may need to take certain medicines, such as aspirin and other
antiplatelet medicines that prevent your blood from forming clots. Your
healthcare provider may recommend taking this medicine for a year or
longer after receiving an artery stent to prevent
complications. The most common problems are a stent becoming
blocked, a blood clot forming in an artery stent, or an airway stent
moving out of place.
Types of stents
Stents have different purposes. The materials used in stents can
vary depending on where they will go in the body.
Airway stents
Some stents are used in the airways in the lungs. Airway stents are
usually temporary.
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Metal
stents are made of bare metal or covered with another
material, such as silicone. They can be difficult to remove from
the airways, so they are not common.
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Silicone stents are made of a material that can be
molded to a certain shape. They are more common, because they
are easy to insert and remove. Some silicone stents are 3D
printed and can be custom fit for each person.
Aortic aneurysm stents
Stent grafts are used to treat aortic
aneurysms. The stent graft is typically a tube made of leakproof
polyester with metal mesh underneath. Stent grafts are used in
larger arteries, such as the aorta, and provide a stable channel for
the blood to flow through.
Coronary or carotid artery stents
Some stents are made specifically for the coronary or carotid
arteries.
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Bare metal stents are simple metal mesh tubes that can
be used in both the coronary and carotid arteries.
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Drug-eluting stents are the most common type of stents
used in the coronary arteries. Usually, these stents have a
metal mesh structure and another layer that covers the metal.
The outside layer is coated with medicine that is released into
the artery over time to prevent the artery from narrowing again.
Different types of drug-eluting stents are coated with different
medicines. Sometimes the outer layer is biodegradable, meaning
it breaks down and dissolves over time, leaving only the metal
mesh part of the stent in the artery.
When Do You Need a Stent?
Your healthcare provider may recommend a stent to support a narrow or
weak artery or airway. They will discuss the risks and benefits with
you. Several conditions may lead your provider to recommend a stent.
Aortic aneurysm or dissection
Your healthcare provider may use a stent graft to treat an aneurysm or dissection of
the aorta, the main artery carrying oxygen-rich blood to your body.
Some medical conditions can damage the walls of the aorta. When the
walls are weak, the force of the blood pushing through can cause an
aneurysm or balloon-like bulge in the aorta. The stent graft
supports the weak area of the aorta and helps to prevent the
aneurysm from bursting or tearing the wall of the artery
(dissection). Stent grafts can also help control blood flow after an
injury and stop blood from leaking out of the blood vessel and into
the body. Coronary heart disease
Stents are often used to treat narrowed coronary arteries. In coronary
heart disease, the arteries cannot carry enough oxygen-rich blood to
the heart. Low blood flow to the heart can lead to chest
pain and damage to the heart muscle from a heart
attack.
To understand the causes of coronary heart disease, it helps to learn
about how
the heart works.
Carotid artery disease
The carotid
arteries are
arteries in the neck that carry oxygen-rich blood to the brain. Plaque buildup
in the carotid arteries can cause carotid
artery disease and increase the risk of stroke.
Placing a stent in a narrowed carotid artery can help hold the
artery open and restore normal blood flow to the brain. Peripheral artery disease
In peripheral
artery disease, plaque builds up in the arteries that carry
blood to your legs, arms, or abdomen. Stents can help treat the
narrowed arteries, relieve symptoms, and prevent future health
problems that can result from low blood flow. Lung conditions
Stents can help treat narrowed airways in the lungs. Unlike stents
for arteries, airway stents are usually a temporary solution before
surgery or other more permanent treatments. Silicone stents are easy
to move or remove from the airways and can remain in place for
several years. Metal stents, on the other hand, are harder to remove
the longer they stay in the airway, so they are less commonly used.
There are different reasons why someone may need an airway stent.
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Problems you are born with, also called congenital
conditions, may create the need for an airway stent.
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Infections or conditions such as sarcoidosis can
cause swelling that squeezes the airways. Anything that presses
on the lungs can cause the airways to become narrowed or
blocked.
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Injury to
the airways can occur from intubation, which is performed when a
breathing tube is guided down into the lungs to help you
breathe. Damage from some lung
treatments can also lead to narrowed airways, such as from
a tracheostomy or
if a hole forms where transplanted
lungs were stitched together.
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Tumors can
block the airways. Cancer treatment, such as radiation or
chemotherapy, can sometimes damage the airways too.
To understand the airways, it helps to learn more about how
the lungs work.
When a stent may not be recommended
Your healthcare provider will consider your health, talk to you
about the risks,
and help you make a decision.
An artery stent may not be recommended if:
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Your
condition is mild. Your provider may monitor your
condition, start you on medicine, and recommend heart-healthy
lifestyle changes.
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You
cannot take antiplatelet medicines for the amount of
time needed after the stenting procedure. Antiplatelet medicines
prevent the formation of life-threatening blood clots inside the
stent.
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You
have other medical conditions, such as multiple
narrowed coronary arteries, long-standing kidney disease, or
diabetes. Your provider may recommend coronary
artery bypass graft surgery (CABG) instead.
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You
have a high risk for complications. Age or other risk
factors may lead your provider to recommend a different
treatment instead of a carotid stent, especially if you are over
age 70 or you have a high risk of stroke. Stent grafts may be
riskier for older people and those with conditions such as
kidney or heart
failure.
An airway stent may not be recommended if:
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You
cannot have anesthesia or be sedated.
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You
need other procedures in the future, such as laser
therapy, which can break or burn the stent. An airway stent
can also get in the way if you need lung surgery for other
reasons.
Before You Get a Stent
Your healthcare provider can help decide whether you need a stent by
using certain tests and procedures. If you need
a stent, your provider will talk to you about how to prepare for it.
Diagnostic tests and procedures
To diagnose narrowed arteries or an aortic
aneurysm, your provider may order some of the following heart
tests and procedures.
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Chest
magnetic resonance imaging (MRI) looks for aneurysms in
the aorta. This test works well to find aneurysms and pinpoint
their size and exact location.
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Computed tomography angiography (CTA) and magnetic resonance
angiography (MRA) take pictures of your blood vessels.
These tests may give your provider more information about blood
flow and whether arteries are narrowed or have aneurysms.
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Coronary angiography measures how blood flows through
your coronary arteries. This type of test involves injecting dye
into your blood so that your blood vessels can be seen by X-ray.
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Fractional flow reserve can help determine how narrow
the artery is. This is an added test done during CTA or coronary
angiography to check the blood pressure, or how much force is
needed for the blood to flow through the artery.
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Ultrasound looks at whether plaque has
narrowed or blocked your carotid or peripheral arteries. It is
also used to see whether you have an aneurysm and where it is
located. This painless test uses high-energy sound waves to
create pictures of the insides of your blood vessels.
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Echocardiography (echo or ECG) evaluates the structure
and function of your heart, using sound waves to create moving
pictures.
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Nuclear imaging checks whether the blood is flowing
normally to the heart. Your provider will inject a substance
they can trace through your bloodstream to see whether the heart
is receiving enough blood flow.
To diagnose narrowed airways, you may need some lung
tests and procedures.
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Bronchoscopy determines the location and severity of
the narrowed airway.
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Chest
computed tomography (CT) scans look at whether one of
your airways is being affected by a tumor, pneumonia, mucus, or
other problem.
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Lung spirometry tests measure
how well your lungs are working.
Preparing for the stenting procedure
You may need more tests, such as blood
tests and electrocardiogram, chest X-ray, or chest CT scans, to
prepare for the procedure to place a stent. Tell your provider about
medicines you take, other surgical procedures you have had, and any
medical conditions, such as diabetes, kidney disease, or sleep
apnea.
You will be asleep for most stent procedures, so plan to have
someone else take you home afterward. You may go home the same
day or after a few days, depending on the type of stent and your
other medical conditions.
Before your procedure, you will be given detailed information,
including:
- When to stop eating or drinking
- If and when you should start or stop taking medicines
- When to arrive at the hospital and where to go
- How long you should expect to stay
- What happens during the procedure
- What to expect after the procedure, including potential
complications such as bleeding or soreness
- What to do after the procedure, including what medicines to take
- How to live with your stent(s)
Getting a Stent
Having a stent placed is a minimally invasive procedure, meaning it does
not require a large open incision.
Coronary and carotid artery stenting
Procedures to place a stent to treat coronary and carotid
arteries are
similar. In both, your healthcare provider will use catheterization to
thread a thin tube with a stent and an empty balloon on the end
through the blood vessel to the narrowed or blocked artery. Once the
balloon is in place, filling it with air opens the stent to hold up
the artery walls. Then your provider will empty the balloon of air
again and remove the tube and the empty balloon from the artery.
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Percutaneous coronary intervention (PCI), or
coronary angioplasty ,
opens narrowed or blocked arteries of the heart to treat coronary
heart disease. A coronary stent can be placed during a PCI
to prevent the artery from narrowing again. Sometimes the
procedure is done in an emergency, such as during a heart
attack.
Placing a
stent in a narrowed coronary artery. The coronary arteries
surround the heart and provide oxygen-rich blood to the heart
muscle. To place a stent in a coronary artery narrowed by plaque, a
catheter is inserted with an empty balloon and a stent attached at
the end. The balloon is inflated to push the artery open and open
the stent. Finally, the catheter and balloon are removed, leaving
the stent in place to keep the artery open and prevent it from
narrowing again.
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Carotid artery stenting is a minimally invasive
treatment for severe carotid
artery disease. Usually, the procedure to place a carotid
stent includes temporarily blocking the blood flow from the
narrowed artery to the brain. This helps prevent any pieces of plaque from
reaching the brain and causing a stroke.
Placing a
stent in a narrowed carotid artery in the neck. The carotid
arteries carry oxygen-rich blood to the brain. To place a stent in a
carotid artery narrowed with plaque, a catheter is inserted with a
stent and an empty balloon at the end. In the narrowed area, the
balloon is filled with air to widen the artery and open the stent in
place. After the catheter and balloon are removed, the expanded
stent helps keep the artery open to restore normal blood flow to the
brain.Aortic aneurysm stenting
The procedure to place a stent graft in the aorta to treat
an aneurysm is called endovascular aneurysm repair. Your
healthcare provider inserts a stent graft through a large blood
vessel using
a catheter and guides it up your arteries to the location of the
aneurysm. Once it is in the right place, the stent graft opens up
and attaches to the walls of the aorta. This will seal off the
aneurysm and prevent it from getting bigger or rupturing. After
placing the stent graft, your provider may inject a contrast dye
into your blood and take an X-ray of your aorta to make sure blood
is not leaking into the aneurysm.
Placing a
stent graft in aortic aneurysm. A catheter is inserted into
an artery through a small cut in the upper thigh. The catheter
guides the stent graft to the abdominal aorta. At the aneurysm, the
stent graft expands as the catheter is slowly pulled back out. Once
the stent graft is in place, it allows blood to flow through the
aorta without pushing against the aneurysm’s weak walls.Airway stenting
Bronchoscopy uses a small camera on the end of a long tube to
look inside the airways in your lungs. To do that, your healthcare
provider slides the camera, or bronchoscope, through your nose or
mouth and down your throat into the airways. During the procedure,
your provider can also insert an airway stent or take samples for
diagnostic tests.
If you need a stent, your provider will slide a thin tube that
carries the folded stent along the side of the bronchoscope. Your
provider may also use fluoroscopy, a type of X-ray imaging, or
ultrasound to help guide stent placement. Once it is in the right
area, the stent will expand in the narrowed airway to push it open.
After placing the stent, your provider may check your lungs using a
chest X-ray.
After You Get a Stent
Recovery
Before you leave the hospital, your healthcare provider will give you
instructions to follow at home.
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Take your
medicines according to your provider’s directions. You may
need to take medicines to prevent complications.
For example, antiplatelet medicines can help stop a blood clot from
forming in a coronary stent.
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Resume
normal physical activity and return to work when your
provider says it’s okay. For most people, this can happen within a
few days to a week.
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Make a
follow-up appointment. Your provider will want to check on
your progress and make sure there are no problems.
Possible risks of the stenting procedure
There are risks from placing a stent in an artery, including:
- Allergic reactions to the contrast dye used to look at blood
vessels with X-rays
- Arrhythmia, or an irregular heartbeat
- Bleeding or discomfort where the catheter was inserted
- Damage to blood vessels from the catheter
- Infection
- Rarely, damage to the kidneys from the contrast dye
It is rare for life-threatening problems to happen during a stenting
procedure. However, people who have had other procedures to treat
blocked arteries or who have congestive
heart failure, kidney disease, or diabetes are usually at higher
risk of serious complications, including:
- Blood flow being cut off from the gut or the lower part of the
body during an aortic aneurysm repair
- Heart attack
- Rupture or burst of an aortic aneurysm
- Stroke
- Tear in the artery (dissection)
Risks from airway stent procedures include:
- Arrhythmia
- Cardiac arrest
- Infection
- Migration, or unexpected movement, of the stent
- Needing a tracheostomy because
the airways become blocked
- Pneumothorax
- Respiratory failure
Living With a Stent
If you have a stent because of coronary heart disease or
carotid artery disease, you are still at risk of having a
heart attack or a stroke. Learn the signs
of a heart attack and the signs
of a stroke and call
9–1–1 if you or someone else needs help. Receive routine follow-up care
A stent is a treatment, but it cannot cure your
underlying condition. It is important to have
routine medical care if you have a stent. Ask
your healthcare provider how often you should
schedule office visits and tests.
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Talk about when to follow up with
specialists such as a cardiologist
or pulmonologist. If you have an airway
stent, you may need a bronchoscopy, a chest
X-ray, or a CT scan to confirm that the
stent has not moved. These tests can also
check for signs of complications. If you
have a stent graft to treat an aortic aneurysm ,
you may need regular imaging tests for the
rest of your life to make sure that there is
no blood leaking into the aneurysm and to
monitor your stent graft.
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Take medicines to prevent problems. Do
not change your medicine or skip doses
unless your provider tells you to. After
getting an artery stent, you will need
antiplatelet medicines, or blood thinners, to
prevent blood clots from forming. You may
need to take blood thinners for more than a
month after you get a carotid or peripheral
artery stent or for more than a year after
getting a coronary stent. Antiplatelet
medicines include aspirin, clopidogrel,
dipyridamole, and ticlopidine. Bleeding is a
possible side effect, which can make any
other needed surgery much riskier.
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Ask how long before you can resume normal
physical activity. It will depend
on the type of stent you have and your
health condition before the procedure.
Make healthy lifestyle changes
Your provider may recommend the following healthy
lifestyle changes to lower your risk of
needing future procedures or experiencing
complications such as a heart attack or stroke:
- Aim for a healthy weight
- Stay physically active
- Choose heart-healthy foods
- Manage stress
- Quit smoking and avoid secondhand smoke
- Get enough good-quality sleep
Watch for problems from vascular stents
Be on the lookout for complications from a
coronary stent, carotid stent, or stent graft.
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Blood clots can form within the
stent. Your risk of getting a blood clot is
much higher if you stop taking your blood
thinners before your provider says to do so.
Blood clots can lead to life-threatening
conditions, such as heart attack, stroke,
and venous
thromboembolism.
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Restenosis is a re-narrowing of the
section of the artery where there is a stent.
The artery can become narrow again when
there is too much tissue growth inside it.
With a coronary stent, restenosis can lead
to a heart attack. With a carotid stent, a
stroke can occur. Restenosis may or may not
cause symptoms. If it does occur, you may
need a new stent or another procedure.
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A stent graft can leak or move from
its place. Symptoms may be similar to those
you experienced before the aortic repair
procedure, or you may have no symptoms. Your
provider will use imaging to monitor your
stent graft.
Watch for problems from lung stents
Call your provider right away if you experience
any of the following symptoms:
- Breathing problems
- Changes in your cough
- Coughing up blood
- High fever
- Persistent bad breath
Those symptoms may result from complications of
your airway stent.
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An airway stent can migrate, or
move, and may require another procedure to
fix or remove it. This occurs more often
with silicone stents.
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Lung infection is another possible
complication from an airway stent.
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Mucus can get caught in the stent
and block it.
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Tissue can grow into the stent if
the condition that caused your narrowed
airway causes it to become blocked again.
This happens more often with metal stents.
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