Coronary artery bypass graft surgery is done to go around a portion of an artery that has been narrowed or blocked by plaque buildup (atherosclerosis). It is a treatment for coronary artery disease.

The narrowed or blocked portion of the artery is bypassed using a blood vessel taken from elsewhere in the body (usually the chest or leg). Blood is redirected through the new blood vessel, restoring blood flow to the affected portion of the heart muscle.