How Are Stents Used?

For the Coronary Arteries

In a condition called coronary heart disease (CHD), or coronary artery disease, a fatty substance called plaque (plak) can build up inside the coronary (heart) arteries. Plaque narrows the coronary arteries, reducing the flow of oxygen-rich blood to the heart muscle.

High blood cholesterol, high blood pressure, diabetes, and smoking may lead to CHD. When your coronary arteries are narrowed or blocked, oxygen-rich blood can't reach your heart muscle. This can cause angina (an-JI-nuh or AN-juh-nuh; chest pain) or a heart attack.

During angioplasty, doctors use an expanding balloon inside the artery to compress plaque and widen the passage. Angioplasty improves blood flow to the heart, which reduces angina and other CHD symptoms.

Unless an artery is too small, doctors usually place a stent in the treated portion of the artery during angioplasty. The stent supports the inner artery wall and reduces the chance of the artery becoming narrowed or blocked again. A stent also can support an artery that was torn or injured during angioplasty.

When stents are used in coronary arteries, there's about a 10 to 20 percent chance that the arteries will renarrow or close in the first year after angioplasty. When stents aren't used, the risk of the arteries closing can be twice as high.

For the Carotid Arteries

Both the right and left sides of your neck have blood vessels called carotid (ka-ROT-id) arteries. These arteries carry blood from the heart to the brain. Plaque also can narrow the carotid arteries. When this happens, the condition is called carotid artery disease.

Plaque deposits in the carotid arteries limit blood flow to the brain and put you at risk for stroke. The same factors that raise your risk for CHD also increase your risk for carotid artery disease.

Stents are used to help keep the carotid arteries fully open after they're widened with angioplasty. How well this treatment works long term still isn't known. Research is ongoing to explore the risks and benefits of carotid artery stenting.

For Other Arteries

The arteries in the kidneys may become narrowed. This reduces blood flow to the kidneys, which can affect their function and ability to control blood pressure. This can cause severe high blood pressure.

Plaque can narrow the arteries in the arms and legs over time. When this happens, the condition is called peripheral arterial disease, or P.A.D.

This narrowing can cause pain and cramping in the affected limbs. If the narrowing is severe, it can completely cut off blood flow to a limb, which could require surgery.

To relieve these problems, doctors may do angioplasty on a narrowed kidney, arm, or leg artery. This procedure often is followed by placing a stent in the treated artery. The stent helps keep the artery fully open.

For the Aorta in the Abdomen or Chest

The major artery coming out of the heart that supplies blood to the body is called the aorta. The aorta travels through the chest and down into the abdomen. Over time, some areas of the aorta's walls can become weak. These weakened areas can cause a bulge in the artery called an aneurysm.

An aorta with an aneurysm can burst, leading to potentially deadly internal bleeding. When aneurysms occur, they're usually in the part of the aorta in the abdomen.

To help avoid a burst, doctors may place a fabric stent in the weakened area of the abdominal aorta. The stent creates a stronger inner lining for the artery.

Aneurysms also can develop in the part of the aorta in the chest. These aneurysms also can be treated with stents. How well these stents work over the long term still isn't known.

To Close Off Aortic Tears

Another problem that can develop in the aorta is a tear in its inner wall. Blood can be forced into this tear, causing it to widen.

The tear can reduce blood flow to the tissues that the aorta serves. Over time, the tear can block blood flow through the artery or burst. When this occurs, it's usually in the part of the aorta that's in the chest.

Fabric stents are being developed and used experimentally to prevent aortic tears by stopping blood from flowing into the tear. A fabric stent placed within the torn area of the aorta can help restore normal blood flow and reduce the risk of a burst aorta. Researchers are still studying stents to treat aortic tears.