Working around the clock, a CABG surgery done on a patient with ischemic heart disease! CABG (Coronary artery bypass grafting) surgery entails grafting portions of a patient's native blood vessels to bypass obstructed coronary arteries. It is performed to reduce the risk for coronary a. disease. Arteries or veins from elsewhere in the patient's body are grafted to the coronary arteries to bypass atherosclerotic narrowings and improve the blood supply to the myocardium (heart muscle). Typically, a section of the saphenous vein is removed from the leg and sutured from the base of the aorta to a coronary segment downstream from the region is stenosis. If an arterial graft is used, an internal mammary artery is commonly taken. This surgery is usually performed with either the heart stopped (by using cardiopulmonary bypass) or "off-pump", without the heart being stopped.