Monday, February 6, 2012

What Are Stents?

Excerpted from “ Stent,” by the National Heart, Lung, and
Blood Institute (NHLBI,, part of the National
Institutes of Health, July 2009.

A stent could be a tiny mesh tube that’s used to treat narrowed or weakened arteries within the body. Arteries are blood vessels that carry blood off from your heart to different components of your body. you will have a stent placed in an artery as a part of a procedure referred to as angioplasty. Angioplasty restores blood flow through narrowed or blocked arteries. S tents facilitate forestall the arteries from turning into narrowed or blocked once more within the months or years when angioplasty.
You also might have a stent placed during a weakened artery to boost blood flow and to assist forestall the artery from bursting. S tents typically are manufactured from metal mesh, however generally they’re manufactured from material. material stent, additionally referred to as stent grafts, are employed in larger arteries.
Some stents are coated with medicines that are slowly and continuously released into the artery. These stents are referred to as drugging stent. The medicines facilitate forestall the artery from turning into blocked once more.
How Stents Are Used
For the Coronary Arteries
In a condition referred to as coronary heart disease (CHD), or coronary artery disease, a fatty substance referred to as plaque will build up within the coronary (heart) arteries. Plaque narrows the coronary arteries, reducing the flow of oxygen-rich blood to the center muscle. High blood cholesterol, high blood pressure, diabetes, and smoking might cause CHD. When your coronary arteries are narrowed or blocked, oxygen-rich blood can’t reach your heart muscle. this may cause angina (chest pain) or a heart attack. throughout angioplasty, doctors use an expanding balloon within the artery to compress plaque and widen the passage. Angioplasty improves blood flow to the center, that reduces angina and different CHD symptoms. Unless an artery is simply too tiny, doctors typically place a stent within the treated portion of the artery throughout angioplasty. The stent supports the inner artery wall and reduces the prospect of the artery turning into narrowed or blocked once more. A stent can also support an artery that was torn or injured throughout angioplasty. When stent are employed in coronary arteries, there’s a few ten to twenty p.c likelihood that the arteries can re-narrow or shut within the 1st year when angioplasty. When stent aren’t used, the danger of the arteries closing will be twice as high.

For the Carotid Arteries
Both the proper and left sides of your neck have blood vessels referred to as carotid arteries. These arteries carry blood from the center to the brain. Plaque can also slender the carotid arteries. When this happens, the condition is named carotid artery disease. Plaque deposits within the carotid arteries limit blood flow to the brain and place you in danger for stroke. a similar factors that raise your risk for CHD additionally increase your risk for carotid artery disease. Stent are used to assist keep the carotid arteries absolutely open when they’re widened with angioplasty. How well this treatment works future still is not known. analysis is ongoing to explore the risks and edges of carotid artery stinting.
For different Arteries
The arteries within the kidneys might become narrowed. This reduces blood flow to the kidneys, which might have an effect on their perform and skill to regulate blood pressure. this may cause severe high blood pressure.
Plaque will slender the arteries within the arms and legs over time. When this happens, the condition is named peripheral arterial disease, or P.A.D. This narrowing will cause pain and cramping within the affected limbs. If the narrowing is severe, it will fully interrupt blood flow to a limb, that might need surgery. to alleviate these issues, doctors might do angioplasty on a narrowed kidney, arm, or leg artery. This procedure typically is followed by inserting a stent within the treated artery. The stent helps keep the artery absolutely open. For the Aorta within the Abdomen or Chest the main artery starting of the center that provides blood to the body is named the aorta. The aorta travels through the chest and down into the abdomen. Over time, some areas of the aorta’s walls will become weak. These weakened areas will cause a bulge within the artery referred to as an aneurysm. An aorta with an aneurysm will burst, resulting in probably deadly internal bleeding. When aneurysms occur, they’re typically within the a part of the aorta within the abdomen. to assist avoid a burst, doctors might place a material stent within the weakened space of the abdominal aorta. The stent creates a stronger inner lining for the artery. Aneurysms can also develop within the a part of the aorta within the chest. These aneurysms can also be treated with stent. How well these stent work over the future still is not known.
To Close off Aortic Tears
Another downside which will develop within the aorta could be a tear in its inner wall. Blood will be forced into this tear, inflicting it to widen. The tear will scale back blood flow to the tissues that the aorta serves. Over time, the tear will block blood flow through the artery or burst. When this happens, it’s typically within the a part of the aorta that’s within the chest.
Fabric stents are being developed and used experimentally to forestall aortic tears by stopping blood from flowing into the tear. a material stent placed at intervals the torn space of the aorta will facilitate restore traditional blood flow and scale back the danger of a burst aorta. Researchers are still learning stent to treat aortic tears.
Placing Stent
To place a stent, your doctor can build alittle gap during a blood vessel in your groin (upper thigh), arm, or neck. Through this gap, your doctor can thread a skinny, versatile tube referred to as a catheter with a deflated balloon on its finish.
A stent could also be placed round the deflated balloon. The tip of the catheter is threaded up to the narrowed section of the artery or to the aneurysm or aortic tear website. Special x-ray movies are taken of the tube as it’s threaded up into your blood vessel. These movies facilitate your doctor position the catheter.
For Arteries Narrowed by Plaque
Once the tube is within the space of the artery that wants treatment, the doctor can take the subsequent steps:
• Your doctor uses a special dye to assist see narrowed areas of the blood vessel.
• Your doctor inflates the balloon. It pushes against the plaque and compresses it against the artery wall. The absolutely extended balloon additionally expands the encircling stent, pushing it into place within the artery.
• The balloon is deflated and brought out in conjunction with the catheter.
The stent remains in your artery. Cells in your artery eventually grow to hide the mesh of the stent and build an inner layer that appears just like the inside a standard blood vessel. a really slender artery, or one that’s arduous to succeed in with a catheter, might need a lot of steps to put a stent. this sort of artery typically is 1st expanded by inflating alittle balloon. The balloon is then re-moved and replaced by another larger balloon with the collapsed stent around it. At now, your doctor will follow the quality apply of compressing the plaque and inserting the stent. When angioplasty and stent placement are done on carotid arteries, a special filter device is employed. The filter helps keep blood clots and loose items of plaque from passing into the bloodstream and traveling up to the brain throughout the procedure.
For Aortic Aneurysms
The procedure to put a stent in an artery with an aneurysm is extremely kind of like the one used for an artery narrowed by plaque. The stent used to treat an aneurysm is completely different, though. It’s created out of pleated material, typically with one or a lot of little hooks. Once the stent has been placed and expanded to suit tight against the artery wall, the hooks on the stent latch on to the artery wall. This anchors the stent.
The stent creates a brand new inner lining for that portion of the artery. Cells within the artery eventually grow to hide the material and build an inner layer that appears just like the inside a standard blood vessel.
What to Expect before a Stent Procedure
Most stent procedures need an overnight keep within the hospital and somebody to require you home. confer with your doctor the subsequent is sues:
• When to prevent eating and drinking before coming back to the hospital
• What medicines you must or shouldn’t war the day of the procedure
• When to return to the hospital and where to travel
If you have got diabetes, kidney disease, or different conditions, speak along with your doctor concerning whether or not you wish to require any further steps throughout or when the procedure to avoid complications. Before the procedure, your doctor might speak with you concerning medicines you’ll most likely have to be compelled to take when the stent is placed. These medicines facilitate forestall blood clots from forming. It’s necessary that you just savvy long you must take these medicines and why they’re necessary.
What to Expect throughout a Stent Procedure
For Arteries Narrowed by Plaque
This procedure typically takes concerning an hour. It might take longer if stent are inserted into quite one artery throughout the procedure. Before the procedure starts, you’ll get medication to assist you relax. You’ll be on your back and awake throughout the procedure thus you'll be able to follow the doctor’s directions. the world where the catheter is inserted are numbed, and you won’t feel the doctor threading the catheter, balloon, or stent within the artery. you will feel some pain when the balloon is expanded to push the stent into place.
For Aortic Aneurysms
This procedure takes some hours. it always needs a 2- to 3-day keep within the hospital. Before the procedure, you’ll be given medication to assist you relax. If a stent is placed within the abdominal aorta, your doctor might provide medication to numb the world, however you’ll be awake throughout the procedure. If a stent is placed within the chest portion of the aorta, your doctor can possible provide you with medication to create you sleep through the procedure. Once you’re numbed or asleep, your doctor can build alittle cut in your groin (upper thigh). He or she's going to insert a catheter into the blood vessel through this cut.
Sometimes, 2 cuts (one within the groin space of every leg) are required to put material stent that are available 2 components. you'll not feel the doctor threading the catheter, balloon, or stent into the artery.
What to Expect when a Stent Procedure
After either style of stent procedure (for arteries narrowed by plaque or aortic aneurysms), the catheter are removed and also the tube insertion website are bandaged.
A small sandbag or different style of weight could also be placed on high of the bandage to use pressure and facilitate forestall bleeding. You’ll recover during a special care space where your movement are restricted. whereas you’re in recovery, a nurse can check your heart rate and blood pressure frequently. The nurse additionally can see whether or not there’s any bleeding from the insertion website. Eventually, alittle bruise and a few times alittle, arduous “knot” can seem at the insertion website. This space might feel sore or tender for a few week.
You should let your doctor understand if any of the subsequent occur:
• you have got a continuing or great amount of bleeding at the positioning that can’t be stopped with alittle bandage.
• you have got any uncommon pain, swelling, redness, or different signs of infection at or close to the insertion website.
Common Precautions when a Stent Procedure
Blood Clotting Precautions
After a stent procedure, your doctor can possible suggest that you just take aspirin and another anti-clotting medication. These medicines facilitate forestall blood clots from forming within the stent. A blood clot will cause heart attack, stroke, or different serious issues. If you have got a metal stent, your doctor can possible suggest aspirin and another anti-clotting medication for a minimum of one month. If your stent is coated with medication, your doctor might suggest aspirin and another anti-clotting medication for twelve months or a lot of. Your doctor can work with you to work out the simplest course of treatment.
The risk of developing a blood clot considerably will increase if you stop taking the anti-clotting medication too early. It’s necessary to require these medicines for as long as your doctor recommends. He or she might suggest lifelong treatment with aspirin.
If you’re considering surgery for a few different reason whereas you’re on these medicines, visit your doctor concerning whether or not it will wait till when you've got stopped the medication. Anti-clotting medicines might increase the danger of bleeding. additionally to an increased risk of bleeding, anti-clotting medicines will cause different aspect effects, like an allergic rash. visit your doctor concerning a way to scale back the danger of those aspect effects.
Other Precautions
You should avoid vigorous exercise and significant lifting for a brief time when the stent procedure. Your doctor can allow you to understand after you will return to your traditional activities. If you have got a metal stent, you should not have a magnetic resonance imaging (MRI) take a look at at intervals the primary number of months when the procedure. Metal detectors employed in airports and different screening areas don’t have an effect on stent. Your stent should not cause metal detectors to travel off. If you have got an aortic material stent, your doctor can most likely suggest that you just have followup imaging tests (for example, chest x-ray) at intervals the primary year of getting the procedure. when the primary year, he or she might suggest yearly imaging tests.
Risks of getting a Stent
Risks associated with Angioplasty
Angioplasty, the procedure used to put stents, could be a common medical procedure. Angioplasty carries alittle risk of the subsequent serious complications:
• Bleeding from the positioning where the catheter was inserted into the skin
• injury to the blood vessel from the catheter
• Arrhythmia's (irregular heartbeats)
• injury to the kidneys caused by the dye used throughout the procedure
• An hypersensitivity to the dye used throughout the procedure
• Infection
Another downside when angioplasty is simply too a lot of tissue growth
within the treated portion of the artery. this may cause the artery to slender or shut once more, that is named restiveness. This downside typically is avoided with the utilization of drugging stent. These stents are coated with medicines that facilitate forestall an excessive amount of tissue growth. Treating the tissue round the stent with radiation can also forestall tissue growth. For this procedure, the doctor puts a wire through a catheter to where the stent is placed. The wire releases radiation and stops cells round the stent from growing and blocking the artery.
Risks associated with Stent
About one to a pair of p.c of individuals who have a stented artery develop a blood clot at the stent website. Blood clots will cause heart attack, stroke, or different serious issues. the danger of blood clots is greatest throughout the primary few months when the stent is placed within the artery. Your doctor can possible suggest that you just take aspirin and another anti clotting medication, like clopped, for a minimum of one month or up to a year or a lot of when having a stent procedure.
These medicines facilitate forestall blood clots.
The length of your time you wish to require anticlotting medicines depends on the kind of stent you get. Your doctor might suggest lifelong treatment with aspirin. Stent coated with medication, which regularly are used to stay clogged heart arteries open, might increase your risk for probably dangerous blood clots. However, no conclusive proof shows that these stent increase the possibilities of getting a heart attack or dying, if used as suggested.
Risks associated with Aortic Stents within the Abdomen
Although rare, some serious complications will occur when surgery or a material stent is employed to repair an aneurysm within the abdominal region of the aorta. These complications embody the following:
• A burst artery (aneurysm rupture)
• Blocked blood flow to the abdomen or lower body
• Paralysis within the legs owing to interruption of blood flow to the spinal wire (this complication is extremely rare)
Another potential complication is that the material stent moving any down the aorta. This generally happens years when the stent is 1st placed. Such stent movement might need a doctor to put another material stent within the space of the aneurysm.


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