Percutaneous Transluminal Coronary Angioplasty (PTCA)
Topic Highlights
PTCA or balloon angioplasty is a non-surgical procedure to treat a narrowed coronary artery.
The placement of a stent is a common procedure used in PTCA to prevent restenosis.
This visual presentation discusses the coronary arteries, atherosclerosis - a common cause of artery blockage, and explains in detail angiography, balloon angioplasty, and coronary stenting.
The heart is a fist size muscular organ pumping large amounts of blood through its chambers. It depends on small arteries called coronary arteries for nutrients and oxygen. They are the first arteries to arise from the aorta . They encircle the heart and are situated on its surface. There are two main coronary arteries. The larger artery – the left main coronary artery – branches into the left anterior descending supplying the front of the heart, and the left circumflex artery supplying the left side and the back of the heart. The right coronary artery supplies the back of the heart.
Like all arteries, healthy coronary arteries are flexible and smooth, and their inner lining allows a free flow of blood. Over time, fats, cholesterol , calcium and other material circulating in the blood are deposited in the innermost layers of the arterial wall forming plaques . This results in the narrowing and stiffening of arteries called atherosclerosis . Arteries affected with atherosclerosis lose their elasticity and become brittle with the deposition of calcium. With time, the plaques may rupture resulting in blood clots, which may further narrow the artery.
A decrease in the diameter of the artery decreases the amount of oxygenated blood to the heart. Reduced oxygenation to the heart muscle may result in characteristic chest pain called angina . Severe blockage of an artery may result in the death of the heart muscle being supplied by the artery causing a heart attack.
Percutaneous Transluminal Coronary Angioplasty or PTCA is a non-surgical procedure that uses a balloon tipped catheter to widen blocked arteries. Stents are usually combined with angioplasty to help it remain open reducing the chance of reblockage.
Before the procedure, blood tests, ECG and angiography are performed. For an ECG, twelve to 15 electrodes are attached to the arms, legs, neck and chest. The electrodes are glued to the body and record electrical activity of the heart. A mild sedative is given before angiography. An intravenous line is inserted into blood vessels in the groin or arm. A catheter is then inserted into the blood vessel. It is carefully guided into the heart with the help of an X-ray machine . Contrast material is then injected and X-rays are taken. The pictures are called angiograms .
Before the procedure, it is important for the patient to discuss his current medications, history of allergy and bleeding problems. Patients are instructed to avoid food and fluids 4-6 hours before the procedure. Angioplasty is performed in a room similar to that where angiography is performed.
For angioplasty, the part of the groin or arm used for catheterization is sterilized. The procedure is done under local anesthesia. A long, thin hollow flexible tube called the guide catheter is inserted into the femoral artery through a small incision in the leg. This catheter is passed through the aorta to the heart and into the coronary arteries.
After the guide catheter reaches the site of the blockage, a second, thinner catheter is inserted into it. There is a small, deflated balloon at the tip of the second catheter. This catheter is positioned at the site of the blockage. The balloon is then inflated for several seconds. The process is repeated several times. Balloons are inflated in size and duration depending on the size and location of the plaque. The expansion of the balloon pushes the plaque against the artery walls. The artery is thus widened and blood flow improves.
Sometimes, stent angioplasty is done to keep the artery open. A stent is a small, expandable wire mesh tube. Though stents are made of metal, they are rather flexible which helps them fit the normal curvature of the arteries. A balloon tipped catheter with stent is then threaded to the site of the blockage. The balloon is inflated, expanding the stent. Then the balloon is deflated and removed while the stent is implanted into the walls of the blocked artery. The tissue of the blood vessel soon covers the stent. The stents may be coated with medication, which is slowly released to prevent arteries from reblockage. Such stents are called drug-eluting stents.
Angioplasty does not require a major incision since it is a non-surgical procedure and reduces the risks posed by surgery. It does not require general anesthesia. Angioplasty has proved its success with a large percentage of people relieved of angina without any major complications following the procedure.
Bleeding may rarely occur at the incision site. The procedure may damage the artery requiring an emergency bypass surgery . Sometimes the repaired arteries may require repeat angioplasty or surgery due to restenosis .
Angiography is repeated to insure that the procedure was successful. The patient will receive blood-thinning medications to decrease the chances of reblockage. The patient is usually instructed to remain in bed for 6 to 24 hours. During this period, the patient is closely monitored for any complications. A follow-up exam is scheduled to study the improved functioning of the diseased artery.
Though the procedure can successfully repair the damaged artery, it does not treat the underlying cause of the damage. Therefore it is important to take sufficient care to prevent further damage. Take medications as instructed by the doctor. Give up smoking and control diet. Keep hypertension under control. Maintain healthy height to weight ratio. Moderate exercise as advised by the doctor helps prevent angina.