Coronary artery bypass graft surgery (CABG) -- a procedure sometimes referred to as a "cabbage" -- is the most commonly-performed open-heart procedure. This surgery provides relief to patients who have blocked or narrowed arteries due to atherosclerosis.

Bypass surgery is essentially the replacement of a blocked section of coronary artery. The most common material for creating this new pathway is the greater saphenous vein, which is taken from the lower leg. This vein, which runs from just inside the ankle bone to the groin, is long and straight. Since it is just one of a large series of veins in the legs, its function is easily assumed by the other blood vessels in the leg.

Another major vessel used for bypass grafts is the left internal mammary artery, which lies on the undersurface of the sternum (breastbone) and is easily accessed during surgery. The lower end may simply be detached and connected to one of the coronary arteries on the surface of the heart.