What is angioplasty and how it is used?
Angioplasty (or Balloon angioplasty) is an endovascular procedure to widen narrowed or obstructed arteries or veins, typically to treat arterial atherosclerosis. An empty, collapsed balloon, known as a balloon catheter, is passed over a wire into the narrowed locations and then inflated to a fixed size.
The balloon forces expansion of the stenosis (narrowing) within the vessel and the surrounding muscular wall, opening up the blood vessel for improved flow, and the balloon is then deflated and withdrawn. A stent may or may not be inserted at the time of ballooning to ensure the vessel remains open.
Doctors may use angioplasty to
• Reduce chest pain caused by reduced blood flow to the heart
• Minimize damage to heart muscle from a heart attack
• Many people go home the day after angioplasty, and are able to return to work within a week of coming home.
What Happens During Angioplasty?
Angioplasty is performed in the cardiac catheterization laboratory, or “cardiac cath lab,” in a hospital. The physician who performs the procedure is called an interventional cardiologist, a heart doctor with additional education, training and experience in treating cardiovascular problems with thin, flexible tubes called catheters. Before the procedure, your interventional cardiologist will review any risks of the procedure and the anesthesia that will be used, as well as obtain your informed consent, which gives your physician permission to perform the procedure.
You will lie on a table and be mildly sedated to help you relax, but you will remain awake throughout the procedure. The process below describes angioplasty forcoronary artery disease (CAD). Angioplasty for other conditions is similar, but you can learn more by reading about treatments for those specific conditions in their condition centers on this website and by asking your physician for details about the procedure.
1.Accessing the Artery
cardiologist will use a small needle to inject lidocaine (an anesthetic that makes you numb but doesn’t make you sleep) in the upper leg or in the arm. (This needle prick could be the only pain you will feel throughout the procedure.) The femoral artery in the upper leg – near where your leg bends from the hip – is one of the blood vessels doctors commonly use to insert the catheter and thread it through the arteries to the heart to perform angioplasty. Instead of the femoral artery, your doctor may choose to insert the catheter in the radial artery in the wrist.
From this access point in your leg or arm, a catheter is threaded through the arteries to your heart. (Since there are no nerves in your arteries, you will not feel the catheter.) An x-ray camera is used to project images of your arteries onto a television screen, and these images help the interventional cardiologist guide the catheter to the blockage in the artery.
When the catheter is properly positioned, the interventional cardiologist injects a contrast dye (also called radiographic contrast agent) through the catheter into the heart and its arteries. Most people do not feel the dye injection. However, some feel minor discomfort or a warm sensation, typically lasting only a few seconds, in their chest. A few feel lightheaded or nauseous.
2.Treating the Blockage in the Artery
If a blockage is found, a tiny, thin wire (called guidewire) is passed across the narrowed segment. It serves as a support for positioning the tiny balloon across the blockage. Next, a long, thin flexible tube (balloon catheter) with a small uninflated balloon at its tip is threaded through the guiding catheter, over the guidewire and into the artery to where the artery is blocked.
Once in position, the balloon is inflated. (The balloon may be inflated several times.) As the balloon inflates, it flattens the plaque against the wall of the artery. Some patients feel minor discomfort when it is inflated. If you have more than minor discomfort, medication can be given to relieve the pain. As the balloon inflates, plaque that extends into the wall of the artery may tear or crack. This is normal and necessary.
Once the balloon is deflated, x-ray pictures are taken to ensure the blockage is gone. When the balloon catheter is removed, final x-ray pictures are made.
3.After the Procedure
At the end of the procedure, the care team will work to close the puncture site where the catheter was inserted. For access sites in the upper leg, manual pressure is applied, sometimes in conjunction with a closure device (when the anatomy is suitable). Common examples of closure devices include a collagen plug or a stitch, each of which is designed to close up the hole in the blood vessel. Closure devices may increase patient comfort and decrease the time that the patient needs to remain on bed rest after the procedure, but in general, they have not been found to decrease the rate of bleeding.
If an artery in the arm was used to perform the procedure, the closure devices are slightly different from those used in the leg and generally consist of bands that go around the wrist, with either air or compounds that stop bleeding in the band.
Click here to see pictures of these devices and learn more about some of the tools interventional cardiologists when performing angioplasty and stenting to treat patients. You can also learn more about the different types of stents here to learn more about the different types of stents.
What Types of Interventional Procedures Are Used in Angioplasty?
There are several types of interventional procedures which your doctor may use when performing angioplasty. They include:
• Balloon angioplasty.
During this procedure, a specially designed catheter with a small balloon tip is guided to the point of narrowing in the artery. Once in place, the balloon is inflated to compress plaque against the artery wall and stretch the artery open to increase blood flow to the heart.
A stent is a small metal mesh tube that acts as a scaffold to provide support inside your coronary artery. A balloon catheter, placed over a guide wire, is used to insert the stent into the narrowed coronary artery. Once in place, the balloon tip is inflated and the stent expands to the size of the artery and holds it open. The balloon is then deflated and removed while the stent stays in place permanently. Over a several-week period, your artery heals around the stent. Stents are commonly placed during interventional procedures such as angioplasty to help keep the coronary artery open. Some stents contain medicine and are designed to reduce the risk of reblockage (restenosis). The doctor will determine if this type of stent is appropriate for your type of blockage.
A special catheter, with an acorn-shaped, diamond-coated tip, is guided to the point of narrowing in your coronary artery. The tip spins around at a high speed and grinds away the plaque on your artery walls. The microscopic particles are washed away in your blood stream and filtered out by your liver and spleen. This process is repeated as needed to allow for better blood flow. This procedure is rarely used today because balloon angioplasty and stenting have much better results and are technically easier for the cardiologist to perform.
The catheter used in this procedure has a hollow cylinder on the tip with an open window on one side and a balloon on the other. When the catheter is inserted into the narrowed artery, the balloon is inflated, pushing the window against the plaque. A blade (cutter) within the cylinder rotates and shaves off any plaque that protruded into the window. The shavings are caught in a chamber within the catheter and removed. This process is repeated as needed to allow for better blood flow. Like rotablation, this procedure is rarely used today.
• Cutting Balloon.
The cutting balloon catheter has a special balloon tip with small blades. When the balloon is inflated, the blades are activated. The small blades score the plaque, then the balloon compresses the plaque against the artery wall.
Uses of Angioplasty
A coronary angiogram (an X-ray with radio-opaque contrast in the coronary arteries) that shows the leftcoronary circulation. The distal left main coronary artery (LMCA) is in the left upper quadrant of the image. Its main branches (also visible) are the left circumflex artery (LCX), which courses top-to-bottom initially and then toward the centre-bottom, and the left anterior descending (LAD) artery, which courses from left-to-right on the image and then courses down the middle of the image to project underneath the distal LCX. The LAD, as is usual, has two large diagonal branches, which arise at the centre-top of the image and course toward the centre-right of the image.
Percutaneous coronary intervention (PCI), commonly known as coronary angioplasty is a therapeutic procedure to treat the stenotic(narrowed) coronary arteries of the heart found in coronary heart disease. These stenotic segments are due to the buildup ofcholesterol-laden plaques that form due to atherosclerosis. PCI is usually performed by an interventional cardiologist.
Treatment with PCI for patients with stable coronary artery diseasereduces chest pain, but does not reduce the risk of death, myocardial infarction, or other major cardiovascular events when added to optimal medical therapy.
Peripheral angioplasty refers to the use of a balloon to open a blood vessel outside the coronary arteries. It is commonly done to treatatherosclerotic narrowings of the abdomen, leg and renal arteries caused by peripheral artery disease. Often, peripheral angioplasty is used in conjunction with peripheral stenting and a atherectomy.
Carotid artery stenosis is treated with angioplasty in a procedure called carotid stenting for patients at high-risk for carotid endarterectomy.
Renal artery angioplasty
Atherosclerotic obstruction of the renal artery can be treated with angioplasty with or without stenting of the renal artery.Renal artery stenosis can lead to hypertension and loss of renal function.
Angioplasty is occasionally used to treat venous stenosis, such as stenosis of the subclavian vein caused by thoracic outlet syndrome.
If you have coronary artery disease, the arteries in your heart are narrowed or blocked by a sticky material called plaque. Angioplasty is a procedure to restore blood flow through the artery.
You have angioplasty in a hospital. The doctor threads a thin tube through a blood vessel in the arm or groin up to the involved site in the artery. The tube has a tiny balloon on the end. When the tube is in place, the doctor inflates the balloon to push the plaque outward against the wall of the artery. This widens the artery and restores blood flow.
Dr Atul Chowdhury