INTRODUCTION OF ANGIOPLASTY
Angioplasty is the fundamental technique that underpins a lot of what we do in interventional radiology. With regard to the use of balloon angioplasty, when Charles Dotter went from using catheters from their original diagnostic use to demonstrating that they could be tools for therapeutic intervention, this was really the birth of interventional radiology as we now know it. The genesis of angioplasty led to all of the other things that we recognise in modern interventional therapy. As it stands 50 years later, the technique has broad applications in terms of peripheral vascular disease and has fundamentally altered the treatment of aortoiliac disease (with or without stenting) and the interventional treatment of critical limb ischaemia. In the UK, critical limb ischaemia has been flagged up as a very important disease entity and there is currently a major focus on raising awareness of the condition and developing strategies to reduce amputation rates.
INDICATION OF ANGIOPLASTY
- Some of the indications for cardiac catheterization procedure are –
- Unstable angina or Chest pain [uncontrolled with medications or after a heart attack]
- Heart attack
- Before a bypass surgery
- Abnormal treadmill test results
- Determine the extent of coronary artery disease
- Disease of the heart valve causing symtpoms (syncope, shortness of breath)
- To monitor rejection in heart transplant patients
- Syncope or loss of consiousness in patients with aortic valve disease
TYPES OF ANGIOPLASTY
Peripheral angioplasty refers to the use of a balloon to open a blood vessel outside the coronary arteries. It is commonly done to treat atherosclerotic narrowings of the abdomen, leg and renal arteries caused by peripheral artery disease. Often, peripheral angioplasty is used in conjunction with peripheral stenting and aatherectomy.
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.
TYPES OF PERCUTANEOUS TRANSLUMINAL CORONARY ANGIOPLASTY (PTCA)
- Balloon angioplasty
- Carotid artery angioplasty
- Cerebral angioplasty
- Coronary artery stent
- Laser angioplasty
- PTA of the Femoral Artery
Balloon angioplasty is a common method of treatment that passes a thin, long tube, known as a catheter, into an obstructed artery through a small cut in the thigh or arm. The catheter is guided through the blood vessels into the artery with the help of a X-ray that shows the movement of the catheter.
Once inside the narrowed artery, a balloon, which is attached to the tip of the catheter, is inflated. The expanded balloon presses against the plaque, flattening it and widening the artery. Blood flow is then restored to normal once the artery is clear. It is normal for discomfort in the chest to occur when the balloon is inserted.
Stents are small metal devices that are placed by a catheter after the angioplasty procedure is complete. A stent remains in the treated artery in order to prevent it from narrowing again. In most cases, stents have proven to be beneficial for those who receive them, but in rare cases when someone has a weak heart, blood clots can develop due to the stent. Stenting is most commonly used in balloon angioplasty.
CAROTID ARTERY ANGIOPLASTY
Interventional cardiologists, radiologists or vascular surgeons perform carotid artery angioplasty to open the clogged arteries in your neck to prevent or treat stroke. They use a long, thin tube called a catheter that has a small balloon on its tip. They inflate the balloon at the blockage site in the carotid artery to flatten or compress the plaque against the artery wall.
Carotid angioplasty is often combined with the placement of a small, metal, mesh-like device called a stent. When a stent is placed inside of a carotid artery, it acts as a support or scaffold, keeping the artery open. By keeping the carotid artery open, the stent helps to improve blood flow to the brain. Carotid angioplasty and stenting are usually performed in patients either because they are not candidates for the traditional surgery (carotid endarterectomy) or because the procedure is felt to be less risky than the traditional surgery.
Cerebral angiography, also called cerebral arteriogram, is a diagnostic test that can help your doctor find blockages in the blood vessels of your head and neck. These blockages can lead to a stroke or aneurysm.
Using the catheter (a long, flexible tube), your doctor will inject a contrast dye into your carotid artery. The carotid artery is the blood vessel in your neck that carries blood to your brain. The contrast material helps the X-ray create a clear picture of your blood vessels so that your doctor can identify any blockages.
Laser angioplasty is similar to balloon angioplasty, but instead of a balloon-tipped catheter, one with a laser at the tip is used. The laser is guided to the blockage, then used to destroy the plaque, layer by layer, by vaporizing it into gaseous particles.
The laser can be used alone, or in combination with balloon angioplasty. If it is teamed up with balloon angioplasty, with the balloon inserted first to attack the hard plaque. The first laser device (the “excimer laser”) for opening coronary arteries won U.S. governmental approval in 1992 but is not used as frequently as other angioplasty procedures.
PTA OF THE FEMORAL ARTERY
An angiplasty is a procedure we use to restore blood flow through your arteries. A percutaneous transluminal angioplasty (PTA) of the femoral artery is a minimally invasive type of angioplasty, restoring blood flow to your femoral artery.
During a PTA procedure, we will:
- Insert a special catheter (long, hollow tube) into the femoral artery. The catheter has a tiny balloon at its tip.
- Inflate the balloon once we have placed the catheter into the narrowed area of the artery. Inflating the balloon pushes aside the fatty tissue in the artery and makes a larger opening, improving the blood flow.
- Insert a stent (a tiny, expandable metal coil), if necessary, into the newly-opened area of the artery to help keep the artery from narrowing or closing again.
ANESTHESIA OF 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.
PREOPERATIVE PROCEDURE OF ANGIOPLASTY
Preoperative teaching includes instruction about the preoperative period, the surgery itself, and the postoperative period.
Instruction about the preoperative period deals primarily with the arrival time, where the patient should go on the day of surgery, and how to prepare for surgery. For example, patients should be told how long they should be NPO (nothing by mouth), which medications to take prior to surgery, and the medications that should be brought with them (such as inhalers for patients with asthma).
Instruction about the surgery itself includes informing the patient about what will be done during the surgery, and how long the procedure is expected to take. The patient should be told where the incision will be. Children having surgery should be allowed to “practice” on a doll or stuffed animal. It may be helpful to demonstrate procedures on the doll prior to performing them on the child. It is also important for family members (or other concerned parties) to know where to wait during surgery, when they can expect progress information, and how long it will be before they can see the patient.
Knowledge about what to expect during the postoperative period is one of the best ways to improve the patient’s outcome. Instruction about expected activities can also increase compliance and help prevent complications. This includes the opportunity for the patient to practice coughing and deep breathing exercises, use an incentive spirometer, and practice splinting the incision. Additionally, the patient should be informed about early ambulation (getting out of bed). The patient should also be taught that the respiratory interventions decrease the occurrence of pneumonia, and that early leg exercises and ambulation decrease the risk of blood clots.
Patients hospitalized postoperatively should be informed about the tubes and equipment that they will have. These may include multiple intravenous lines, drainage tubes, dressings, and monitoring devices. In addition, they may have sequential compression stockings on their legs to prevent blood clots until they start ambulating.
Pain management is the primary concern for many patients having surgery. Preoperative instruction should include information about the pain management method that they will utilize postoperatively. Patients should be encouraged to ask for or take pain medication before the pain becomes unbearable, and should be taught how to rate their discomfort on a pain scale. This instruction allows the patients, and others who may be assessing them, to evaluate the pain consistently. If they will be using a patient-controlled analgesia pump, instruction should take place during the preoperative period. Use of alternative methods of pain control (distraction, imagery, positioning, mindfulness meditation, music therapy) may also be presented.
Finally, the patient should understand long-term goals such as when he or she will be able to eat solid food, go home, drive a car, and return to work.
PROCEDURE OF ANGIOPLASTY
Your doctor may recommend other procedures to diagnose or treat certain conditions. These include:
- Balloon angioplasty uses a balloon to compress plaque against the artery wall and restore blood flow.
- Coronary angiography allows your doctor to take pictures or images, called an angiogram, of your coronary arteries.
- Minimally invasive bypass grafting provides a new route around diseased coronary arteries with healthy vessels taken from other places in your body. You may have general anesthesia if your doctor combines this surgery with atherectomy.
- Stenting involves inserting a mesh tube (stent) inside the coronary artery. The stent expands and remains in place to keep the artery open after atherectomy.
POSTOPERATIVE PROCEDURE OF ANGIOPLASTY
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.
COMPLICATIONS OF ANGIOGRAPHY
WHAT ARE THE RISKS AND POTENTIAL COMPLICATIONS OF THE PROCEDURE?
Your doctor will discuss the specific risks and potential benefits of the recommended procedure with you.
Atherectomy usually has no complications, but as with any surgery, there is a risk of complications, such as embolization (the dislodgement of debris that blocks the arteries in the lower part of the leg) and perforation. These complications, however, are rare. An unusual complication of atherectomy is the re-blockage of the artery (restenosis) that may occur later, especially if you smoke cigarettes.
Special precautions are taken to decrease these risks, and there may be other possible risks. When you meet with your doctor, please ask questions to make sure you understand the risks of the procedure and why the procedure is recommended.