Stent angioplasty was first performed in the mid-1980s and was approved by the FDA in the mid-1990s. It is now widely used in the treatment of coronary artery disease. This procedure is done under local anesthetic and the heart does not need to be stopped.

The coronary arteries are the vessels that provide the blood supply to the heart tissue. However, these arteries may become blocked with deposits of cholesterol and other fatty substances and this causes the channel to become narrow and hence the flow of blood is slowed. This is known as a hardening of the arteries or arteriosclerosis.

What are coronary arteries?

The heart is nourished by several coronary arteries, which supply the heart’s muscle with blood. There are 4 major arteries and each is responsible for a different region of the heart. These arteries are named... The left coronary artery, the left anterior descending artery, the left circumflex and the right coronary artery. When one of these arteries becomes blocked, a specific area of the heart may become damaged.

Why do coronary arteries become blocked?

Blockages can begin at an early age. Even teenagers may show traces of fat within their coronary arteries. Factors that will speed this process include smoking, diabetes, high cholesterol, high blood pressure, poor diet and lack of exercise. There is also a hereditary factor, which means that the disease runs within certain families. An artery that is 50% blocked will cause a blood flow problem during exertion. A 90% blockage will cause a problem even at rest and a 100% blockage will generally lead to a heart attack.

A stent is attached to the end of a catheter and is inserted into a large blood vessel in the arm or the leg. It is then threaded through the body and guided to the heart. Doctors use a radiological dye to guide the stent and catheter through the body. This way, they will be able to look at a monitor and see exactly where the catheter is located.

What is a catheter?

A catheter is a thin, flexible tube, made of plastic and it is hollow in the middle. It is used to gather information about the heart and/or to carry out treatment procedures. The catheter is threaded through the body via arteries or veins. It is introduced into the body through a small incision in the arm or leg. At the tip of the catheter, there is a sensor and/or surgical instrument and at the other end, measuring devices are used to monitor the heart and collect data.

What is the risk from catheters?

The patient should not feel the movement of a catheter through the body and the risk from their use is very low. However, complication may include excessive bleeding at the incision point, allergic reaction to the dye, infection, blood clots, perforation of a blood vessel, heart attacks and/or strokes.

The stent is guide to the site of the blockage in the coronary artery. Then, a balloon is inflated and this causes the stent to expand. This will push aside the blockage and the artery will be opened. The stent acts like a scaffold and forces the artery to remain open. The balloon is then deflated and the catheter is withdrawn, leaving the stent in place. This allows an adequate amount of blood to flow through the artery and nourish the heart muscle. The whole procedure takes about one to two hours to complete.

What is a stent?

Stents are now used in 70-90% of all cardio-vascular procedures. They are made of metal and are designed to expand and open a blockage in a coronary artery. A stent is left in place after the procedure and the patient will not be able to feel its presence. For a stent have the greatest long-term benefit, the patient should maintain a healthy diet and regular exercise.

What is the risk from a stent?

The biggest problem with stents is the fact they are made of metal and not an organic material. The body senses this metal is not part of the body and will start an inflammatory reaction. Immune cells will then gather around the stent and this may lead to a re-closing or re-stenosis of the artery. The artery itself may also be damaged by the metal stent, and this may also lead to an inflammatory response. The patient will be given one or more blood-thinning agents to help prevent this reaction and allow the artery to remain open.