Coronary artery bypass surgery

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Coronary artery bypass surgery

Coronary bypass surgery — The gold standard surgical treatment for coronary artery disease.

Coronary bypass surgery is a common procedure used to divert blood around blocked arteries in the heart. Coronary bypass surgery remains one of the gold standard surgical treatments for coronary artery disease.

Just like all the other organs in your body, your heart needs blood and oxygen to do its job. Coronary arteries snake across the surface of your heart, delivering a constant supply of much-needed blood and oxygen to the heart muscle. When one or more of these arteries becomes narrowed or blocked, blood and oxygen are reduced and heart muscle is damaged.

Coronary bypass surgery uses a healthy blood vessel harvested from your leg, arm, chest or abdomen and connects it to the other arteries in your heart so that blood is bypassed around the diseased or blocked area.

Who is it for?

If lifestyle changes and medication haven't relieved your symptoms or if your narrowed coronary arteries put you at imminent risk of a heart attack, you and your doctor will need to consider whether coronary bypass surgery or another artery-opening procedure such as angioplasty is right for you.

Bypass surgery is an option if:

  • You have debilitating chest pain caused by narrowing of several of the arteries that supply your heart muscle, leaving the muscle short of blood during light exercise or at rest. Sometimes angioplasty and stent placement will bring relief in this situation, but for some, bypass is the best option.
  • You have more than one diseased coronary artery and the heart's main pump — the left ventricle — is functioning poorly.
  • Your left main coronary artery is severely narrowed or blocked. This artery feeds blood to the left ventricle.
  • You have an artery blockage for which angioplasty isn't appropriate, you've had a previous angioplasty or stent placement hasn't been successful, or you've had angioplasty but the artery has narrowed again (restenosis).

Coronary bypass surgery doesn't cure the underlying disease process called atherosclerosis or coronary artery disease. Even if you have bypass surgery, lifestyle changes are still necessary and an integral part of treatment after surgery. Lifestyle changes — especially smoking cessation — are crucial to reduce the chance of future blockages and heart attacks, even after successful bypass surgery. In addition, you will likely need to make other lifestyle changes, such as reducing certain types of fat in your diet, increasing physical activity, and controlling high blood pressure, diabetes and other risk factors for heart disease. Medications are routine after heart surgery to lower your blood cholesterol, reduce the risk of developing a blood clot and help your heart function as well as possible.

How do you prepare?

To prepare for coronary bypass surgery, your doctor will give you specific instructions about any dietary changes or activity restrictions you should follow before surgery. You'll need several pre-surgery tests, often including chest X-rays, blood tests, an electrocardiogram and a coronary angiogram, which is a special type of X-ray procedure that uses dye to visualize the arteries that feed your heart. Most people are admitted to the hospital the day of surgery.

How is it done?

Most coronary bypass surgeries are done through a large incision in the chest while blood flow is diverted through a heart-lung machine (called on-pump bypass surgery).

The surgeon makes an incision down the center of the chest, along the breastbone. The rib cage is spread open to expose the heart. After the chest is opened, the heart is stopped and a heart-lung machine takes over blood circulation to the body.

The surgeon takes a section of healthy blood vessel, often from inside the chest wall or from the lower leg, and attaches the ends above and below the blocked artery so that blood flow is diverted around the narrowed portion of the diseased artery.

New procedures are being developed and used that may reduce the need for large incisions or a heart-lung machine.

  • Off-pump or beating-heart surgery. This procedure allows surgery to be done on the still-beating heart using special equipment to stabilize or quiet the area of the heart the surgeon is working on. This type of surgery is challenging because the heart is still moving. Because of this, it's not an option for everyone. The long-term outcome of this type of procedure is not yet known.
  • Minimally invasive surgery. In this procedure, a surgeon performs coronary bypass through several smaller incisions in the chest. This technique is usually used only when certain conditions exist. If multiple coronary arteries need to be worked on, it's best to use a conventional approach. Variations of minimally invasive surgery may be called port-access or keyhole surgery.

Two types of grafts

Illustration of two types of grafts

In coronary artery bypass surgery, an artery or vein taken from another part of the body is used as a detour around a blocked coronary artery.

What can you expect during the procedure?

Coronary bypass surgery generally takes between three and six hours and requires general anesthesia. On average, surgeons repair two to four coronary arteries. The number of bypasses required depends on the location and severity of blockages in your heart.

Once you're anesthetized, a breathing tube is inserted through your mouth. This tube attaches to a ventilator, which breathes for you during and immediately after the surgery. While this tube is in place, you're not able to speak. But you can communicate with hand gestures and notes.

Expect to spend a day or two in the intensive care unit after coronary bypass surgery. Here, your heart, blood pressure, breathing and other vital signs will be continuously monitored. The breathing tube will be removed as soon as you are awake and able to breathe on your own. Barring any complicating circumstances, you'll likely be discharged from the hospital within a week. Expect a recovery period of about six to 12 weeks. In most cases, you can return to work after six weeks.


After surgery, most people have improvement or complete relief of their symptoms and remain symptom-free for several years. Over time, however, it's likely that other arteries or even the new graft used in the bypass will become clogged, requiring another bypass or angioplasty.

Although bypass surgery improves blood supply to the heart, it doesn't cure underlying coronary artery disease. Your results and long-term outcome will depend in part on following healthy lifestyle recommendations and taking your medication as directed.

  • Stop smoking.
  • Reduce cholesterol levels.
  • Maintain a healthy weight.
  • Control blood pressure.
  • Manage diabetes.
  • Exercise.


If you're undergoing a scheduled operation to bypass a diseased coronary artery, your risk of death is usually low, but still depends on your overall health. The risk is significantly higher if the operation is done as an emergency or if you have other significant medical conditions such as emphysema, kidney disease, diabetes or peripheral vascular disease. Complications — such as arrhythmias, kidney failure, stroke and infections — also may occur after heart surgery.

Some people experience a decline in memory and other cognitive functions after undergoing coronary bypass surgery. Predictors include older age, high blood pressure, lung disease and excessive alcohol consumption. Of those people who do lose some cognitive ability, most gradually regain their intellectual abilities within six to 12 months. Bypass surgery doesn't cause dementia, but it may worsen any pre-existing mental decline, including early dementia.

Looking ahead

Technical improvements are helping to reduce some of the risks involved with coronary bypass surgery. For example, improvements in the types of materials used in heart-lung machines have reduced the risk of clots. Clots formed in the machine can cause blockages in blood vessels serving the brain, lungs or heart. Further advances may prevent the inflammatory response that follows use of a heart-lung machine.

Another risk of coronary bypass surgery is that plaques — the fatty deposits that accumulate on the inner walls of coronary arteries and other vessels in atherosclerosis — may break loose from the walls of the aorta when it's clamped shut for the heart-lung machine. Debris from the ruptured plaques may lodge in the brain, causing a stroke. By using new imaging techniques, however, surgeons have a better chance of placing the clamps in areas of the aorta that are free of plaques.

Last Updated: 06/15/2006
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