Coronary artery bypass graft surgery (CABG), also called coronary artery bypass, coronary bypass or bypass surgery, is the most common type of heart surgery. More than 300,000 people have successful bypass surgery in the United States each year. 

In this procedure, a section of vein or artery from your leg, chest or another part of your body is used to bypass the blocked or diseased portion of a coronary artery, which brings blood to the muscle of your heart. This creates a new, clear way for the blood to flow to get oxygen to your heart muscle so it can work properly. This type of surgery is done to the outer walls of the heart; it doesn't require opening up the chambers of the heart.

Sometimes people talk about single, double, triple or quadruple bypass surgery. This refers to the number of blocked arteries that had to be bypassed. However, the need for more bypasses doesn't necessarily mean the heart condition is worse.

Typically during bypass surgery, the breastbone (sternum) is divided. The heart itself is stopped and cooled. The blood that normally would be pumped by the heart is sent through a heart-lung machine. Unlike other kinds of heart surgery, the chambers of the heart are not opened during bypass surgery.

A long piece of vein may be removed. Today, Cedars-Sinai heart surgeons use an artery from inside the chest wall (in 95% of cases because studies have shown that it improves long-term survival for the patient). In some cases, a small vessel from the lower arm, the radial artery, may be used for the bypass.

This is called a graft. One end will be attached to the ascending aorta, the large artery that carries oxygen-rich blood from the heart to the rest of the body. The other end of the graft will be attached to a coronary artery below the blocked area. The surgery takes two to six hours depending on the number of bypasses needed.

Cedars-Sinai heart surgeons also perform what is called off-pump or "beating-heart" bypass surgery. For most bypass surgeries, a heart-lung machine is used to do the work of the heart while the surgeon operates on it. In off-pump heart surgery, this machine is not used. New technologies now allow surgeons to stabilize a specific part of the heart, rather than the whole heart muscle. While the surgeon works on the controlled part of the heart, the rest of the organ continues to function. All arteries can be bypassed with this method. The off-pump technique is used for patients who have complications that put them at risk if using the traditional heart-lung machine method of bypass surgery.

Between 20 to 30% of bypass patients need a second bypass operation within 10 years. It is important that you take steps to prevent your heart disease from getting worse. This means limiting the amount of fat and cholesterol in your diet, maintaining a healthy weight, quitting smoking and learning new ways to cope with stress. Your doctor may recommend that you join to strengthen your heart and develop new behaviors.