Coronary artery bypass graft surgery (CABG) is a procedure which is used to treat the coronary artery disease. Coronary artery disease (CAD) is shrinking of the coronary arteries, the blood vessel which will supply nutrients and oxygen to the heart muscle. It is caused due to a buildup of fatty material in the walls of the arteries. The buildup narrows the inside part of the arteries, which will limit the supply oxygen-rich blood to the heart muscle. One of the ways of treating the narrowed or blocked arteries is to bypass the blocked portions of the coronary artery with a healthy blood vessel piece taking it from elsewhere in your body. Grafts or blood vessels are used for the bypass procedure which may be the pieces of from an artery in your chest or vein from the leg. An artery from your wrist can also be used. The doctor will attach one end of the graft above the blockage and the other end below the blockage. Now the blood can bypass the blockage by going through the new graft in order to reach the heart muscle, this process is called as coronary artery bypass surgery. Still, the traditional “open heart” procedure is commonly done and it is often preferred in many situations. In a lot of situations, less invasive techniques have been developed in order to bypass the blocked coronary arteries.