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Angioplasty
What is angioplasty?
Angioplasty is a minimally invasive medical procedure to open up narrowed or blocked arteries from within the arteries themselves rather than through surgery. With the narrowed or blocked section of an artery reopened, blood flow to the organs or tissues served can be restored and pain and other problems diminished or eliminated.
In angioplasty, a specially trained physician threads a very thin catheter — a flexible, hollow tube about the diameter of a strand of spaghetti — through your body's arterial system to the targeted point of narrowing (stenosis) or blockage (occlusion) and inflates a tiny, high-tech balloon on the catheter's tip to widen the channel by pushing its walls outward. To do this, the doctor is guided by a fluoroscopy unit — an x-ray machine that provides real-time images on a monitor. Often, in conjunction with angioplasty, the doctor will place a stent, a tiny tube-shaped metal scaffolding, at the site within the artery to prevent restenosis, or re-closure.
Today angioplasty is applied to vascular problems throughout the body, including the heart, the carotid artery in the neck, the renal arteries serving the kidneys and the blood vessels in the legs.
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What problems is angioplasty used for?
The build-up of plaque within an artery with the result of narrowing the channel and impeding blood flow is called atherosclerosis. Since this process can create vascular issues in several areas of the body, the problems that can lead to an angioplasty procedure can vary.
Angioplasty's best known use perhaps is to treat coronary artery disease, in which arteries nourishing the heart narrow (leading to the pain of angina) or close (leading to heart attack). Coronary artery angioplasty is most likely to be performed by cardiologists specially trained in interventional techniques.
Angioplasty procedures in other areas of the body are performed by appropriately trained physicians.
- In cases of suspected carotid artery disease, the first symptoms may be transient ischemic attacks (TIAs), or temporary symptoms warning of risk of impending stroke. Signs of TIAs can include sudden weakness or paralysis in your face or an arm or leg, sudden loss of coordination, slurred speech, difficulty understanding others and sudden loss of vision. These transient symptoms reflect narrowing or impending blockage of the arteries leading up the sides of your neck to supply blood to the brain. Blockage of blood to the brain precipitates stroke, and immediate treatment — whether angioplasty or surgery — is called for. In this case, angioplasty is most likely to be used for patients who are not good candidates for surgery.
- Angioplasty can be used to open closed or narrowed renal arteries. Elevated blood pressure (renal artery hypertension) or signs of kidney failure can be indications that the arteries supplying blood to one or both kidneys are experiencing narrowing or blockage. An obstacle to successful outcomes in this procedure is that in about 50 percent of cases, damage is also already done to the smaller arteries within the kidney by the time the problem becomes apparent.
- It can be applied to stenosis involving blood vessels in pelvis and lower extremities. Initial symptoms may be pain upon walking or standing — claudication — as well as development of ulcers, or wounds that resist healing largely due to lack of blood supply. The most likely sites for angioplasty for these problems are the iliac arteries at the pelvis, but the procedure may be applicable in some situations to the lower legs. The smaller the vessel being opened, however, the lower the chances of its remaining open over the long term.
- Angioplasty can be used to maintain blood vessel grafts connecting arteries and veins in the arms of renal dialysis patients, who need such connections so that blood can be removed, filtered and replaced during dialysis. Otherwise, they are at risk of closing up periodically.
It is important to emphasize that angioplasty can often resolve the medical consequences of vascular disease, but it does not cure the factors that caused the vascular problems in the first place. Avoiding a repeat of these problems requires perhaps lifestyle changes in diet and exercise patterns, and perhaps medical intervention with drugs to control cholesterol.
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How successful are angioplasty procedures?
Since angioplasty's development in the late 1970s, its uses, techniques and outcomes have steadily been advanced. The success rates vary by location of the problem and the extent of the blockage. Your surgeon can help you with the specifics of your particular case.
In the 1980s, the placement of metal stents to keep channels open was developed, increasing successful outcomes.
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What are the advantages of angioplasty over surgery?
Angioplasty is an alternative to surgery that may enable you to avoid the physical trauma, risks, hospitalization and recovery time involved in some surgery. The procedures can usually be performed under local anesthesia.
In some cases, your doctor may perform angiography — the use of a catheter, medical dye and fluoroscopy — to define the nature and extent of your arterial blockage and go ahead and perform an angioplasty in the same procedure. In others, he or she may use angiography to image your blockage and use the information to decide whether angioplasty should be done in a follow-up procedure or whether surgery is more appropriate. For more information on angiography, click here. For more information on vascular surgery, click here.
Angioplasty usually leaves open the option of repeating the procedure if the first effort proves to be unsuccessful, and of still undergoing surgery in the event your arterial problems are not resolved by angioplasty.
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What happens in the procedure?
Performing your angioplasty procedure will be a specially trained physician, usually assisted by a technician and a nurse. You'll most likely remain awake during your procedure, with a sufficient amount of sedative to keep you comfortable. You'll receive local anesthetic at the site of the incision through which the catheter will be introduced — usually the femoral artery at a point just below the groin (this area will be shaved and sterilized before the incision is made).
The procedure will take place in the angiography unit, where you will lie on your back on a table flanked by a "C-arm" fluoroscopic device and monitors on which the radiologist can observe the images it generates. Most of the time, the room will be kept somewhat dark to make it easier for the images on the monitors to be seen.
The first part of the procedure follows the same process as angiography. Guided by the fluoroscopic images on the monitors, the interventional radiologist will thread a guide catheter through your blood vessels to the targeted location. The medical dye will be injected and images of your arterial blockage studied.
Then your doctor will insert the thinner balloon-tipped angioplasty catheter through the guide catheter to the point of the stenosis, where the balloon is inflated. Often, the process of inflating the balloon for about 30 seconds and then deflating it is done several times before the balloon-catheter is withdrawn. The angiographic imaging with dye is then done again to study the resulting blood flow. After this a stent may be placed to support the newly widened site.
Occasionally during the procedure you may feel some minor, temporary sensations — a slight stinging as the pain medication is first injected, warmth when the dye is first injected, a brief headache. When the balloon is inflated, you may feel pain temporarily near the site of the angioplasty.
Usually, the procedure takes between one and three hours, depending on where the targeted location is and its nature. Once the catheter is withdrawn, your nurse will apply pressure for 10 to 20 minutes to the spot where the catheter was inserted to prevent bleeding and give blood time to clot at the site.
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How do stents work?
Stents are tiny, cylinder-shaped metal scaffolding designed to be inserted at the site of an angioplasty to prevent restenosis and keep the newly widened space open (A stent can also be used without angioplasty, placed by itself as an alternative measure).
Two types of stents are currently in use — one compressed and fitted over the balloon so that it is expanded to fit into the new space when the balloon is expanded, the other designed to expand by itself when released from the catheter.
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What is restenosis?
Restenosis is the repeat closure of a narrowed or blocked segment of artery that has been opened by angioplasty. Over time the stenosis may redevelop as plaque again builds up, something that occurs in about 30 to 35 percent of angioplasty-only procedures. In some cases, collapse of the widened space may result, sometimes very quickly, when the walls of the artery are weakened by the balloon inflation.
The use of stents was developed as a means of preventing restenosis, with some success. The character of stents continues to be refined. While the first plain metal stents dealt effectively with the problem of re-closure due to wall collapse, restenosis still occurred over a six-month-month period in about 25 percent of stent recipients. In stents, the restenosis often reflects more the growth of muscle tissue over the devices (just as scar tissue builds up over a wound).
To deal with this, researchers have developed stents coated with drugs that can be released slowly over time to prevent the build-up of the "scar tissue." These are currently available only for heart (coronary) patients in the U.S.
An additional factor in restenosis is the location and size of the artery in quiestion. Generally, the larger arteries tend to remain opened longer than smaller arteries. For example, the iliac arteries serving the pelvis and legs stay open much longer than arteries below the knee.
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What should I do to prepare for my angioplasty procedure?
Prior to your procedure you probably will have a blood test checked to make sure your kidneys are normal. You should stop taking any medications that may thin your blood, and you should be sure to tell your caregivers if you are pregnant, have asthma, have a bleeding problem or are allergic to iodine (the substance used in the dye), to medications or to any other substance, even shellfish. Diabetic patients on certain medications may be asked to stop taking them for a few days.
You should not eat or drink for four to eight hours before your procedure.
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What happens following the procedure?
You will be kept in the recovery area for six to eight hours, possibly being kept in the hospital overnight. If your catheter was inserted through your femoral artery, during this time it is important for you to keep your leg straight to prevent the incision site from bleeding. You should let your nurse know if you experience any bleeding, swelling or pain.
You should make certain you have a family member or friend available to drive you home from the hospital, as you cannot drive yourself. At home, you should rest and drink plenty of fluids. You shouldn't take a hot bath or shower for at least 12 hours and you should avoid driving for 24 hours, smoking for at least 24 hours and strenuous exercise for several days.
You will be asked to take aspirin or other blood-thinners for several weeks to protect any stent that has been placed.
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What are the risks associated with the procedure?
Overall, angioplasty is a very safe procedure, but like any medical procedure there are some small risks associated with undergoing it.
- Allergic reaction to the iodine used to make up the medical dye, or to the anesthesia used. This can range from mild itching to severe difficulties breathing. This is why it is important to let your medical team know of any allergies
- A slight risk of damage to an arterial wall, or of dislodging a blood clot or piece of plaque from an arterial wall that could block an artery and cause damage to an organ such as the brain or an arm or leg.
- Possible excessive bleeding at the insertion point incision.
- Injury to the kidneys, or worsening of an existing kidney problem as the medical dye is excreted from the body.
- A slight risk of injury from radiation. Modern technology uses very low levels of radiation, and lead shielding is also used when appropriate for areas not being imaged.
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How should I evaluate the risks and benefits of an angioplasty procedure?
While there are some slight risks associated with angioplasty, as there are with any medical procedure, there are many benefits to it as an alternative to surgery.
Angioplasty may enable you to avoid the physical trauma, risks, longer hospitalization and recovery time involved in some surgery. Your procedure can be performed under local rather than general anesthesia.
Additionally, angioplasty carries with it the advantage that it leaves open the possibility of repeat angioplasty in the event the first procedure fails, and the option of resorting to surgery if your arterial problems still cannot be resolved by this minimally invasive technique.
Again, it is important to emphasize that angioplasty can often resolve the medical consequences of vascular disease, but it does not cure the factors that caused the vascular problems in the first place. Avoiding a repeat of these problems requires perhaps lifestyle changes in such areas as diet and exercise patterns, and perhaps medical intervention such as use of drugs to control cholesterol.
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For additional information:
You can find additional information about angioplasty at web sites sponsored by government agencies, societies and healthcare institutions. It should perhaps be noted that the World Wide Web is open to many sources posting questionable information and promises, and you are encouraged to seek information from established, reputable organizations.
Likely sources include:
Angioplasty.org (a site more geared to coronary angioplasty but with information relevant to all angioplasty)
www.angioplasty.org
Radiological Society of North America
www.radiologyinfo.com
The Society of Interventional Radiology
www.sirweb.com
The Vascular Disease Foundation
www.vdf.org
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