Coronary artery bypass graft, known as CABG, is an open-heart operation. During the surgery, veins or arteries are taken from another part of your body and used to create a bypass, which is like a detour, around your heart's blocked arteries. More than 600,000 CABG surgeries are done in the United States each year. People often name this surgery by the number of blood vessels that have been bypassed. For example, if two arteries were involved, they would call it a double bypass. If three arteries are blocked and corrected, it's called a triple bypass. Treating four blocked arteries with this surgery is called a quadruple bypass.