Coronary Artery Bypass Grafting (CABG), also called bypass surgery, is the most commonly performed procedure by surgeons. When atherosclerosis develops in the coronary arteries, flow of blood through these vessels is blocked, and the blood supply to heart muscle is jeopardized. If the blockages are significant enough, the end result will be a heart attack or sudden death. CABG is an operation that is designed to re–route the blood around these blockages to prevent a heart attack or sudden death. Conventionally, an artery from behind the breastbone, or veins from the legs are used to "bypass" the blood around the coronary artery blockages.
The operation takes 2–3 hours to perform, and begins after general anesthesia is induced. Patients are completely asleep during the entire course of the operation. Physician assistants remove saphenous vein through incisions in the legs (see Figure 1). The length of the incision is dependent upon the length of vein required to complete the necessary number of "bypasses" (i.e., 5 bypasses require more vein than 2 bypasses). There are many "redundant" veins in the leg. Once some vein is removed, the other veins in the leg take over for the missing vein. Once the vein has been removed from the leg, it has the appearance of a long tube or "conduit". The vein will be divided into shorter segments, each of which will be used for individual bypasses.
As vein is removed from the leg by a physician assistant, the surgeon simultaneously opens the chest by dividing the breast bone or sternum, affording excellent exposure of the heart (see Figure 2). An artery behind the sternum, the left internal mammary artery (LIMA) is taken down and one end prepared for bypass grafting (see Figure 3). Tubes or cannulae are inserted into the heart and major blood vessels surrounding the heart in preparation for cardiopulmonary bypass with the heart–lung machine.