If you have coronary artery disease (CAD), the arteries that supply blood and oxygen to the heart muscle become hardened and narrowed. If lifestyle changes and medicines don't help, your doctor may recommend coronary artery bypass surgery.

The surgery uses a piece of a vein from the leg or artery from the chest or wrist. The surgeon attaches this to the coronary artery above and below the narrowed area or blockage. This allows blood to bypass the blockage. Some people need more than one bypass.

You may need bypass surgery for various reasons. Another procedure for CAD, angioplasty, may not have widened the artery enough. In some cases, the angioplasty tube can't reach the blockage.

A bypass also can close again. This happens in more than 10 percent of bypass surgeries, usually after 10 or more years.

Overview

CABG is the most common type of open-heart surgery in the United States, with more than 500,000 surgeries performed each year. Doctors called cardiothoracic (KAR-de-o-tho-RAS-ik) surgeons perform this surgery.

CABG isn’t used for everyone with CAD. Many people with CAD can be treated by other means, such as lifestyle changes, medicines, and another revascularization procedure called angioplasty.

CABG may be an option if you have severe blockages in the large coronary arteries that supply a major part of the heart muscle with blood—especially if the heart’s pumping action has already been weakened.

CABG may also be an option if you have blockages in the heart that can’t be treated with angioplasty. In these situations, CABG is considered more effective than other types of treatment.