Coronary artery bypass surgery is a treatment option for ischemic heart disease which is when too little blood reaches the heart muscle. Coronary surgery is recommended for:
- Disease of the left main coronary artery
- Disease of three or more vessels (triple vessel disease)
- Cases in which nonsurgical management (medication, angioplasty or stenting) hasn't worked
Coronary arteries are the small blood vessels that supply the heart muscle with oxygen and nutrients. Fat and cholesterol can build up inside these small arteries leading to them gradually becoming clogged. This buildup of fat and cholesterol plaque is called atherosclerosis.
When one or more of the coronary arteries becomes partially or totally blocked, the heart does not get enough blood. This is called ischemic heart disease or coronary artery disease (CAD). It can cause chest pain (angina). Heart bypass surgery creates a detour or "bypass" around the blocked part of a coronary artery to restore the blood supply to the heart muscle. The surgery is commonly called Coronary Artery Bypass Graft, or CABG (pronounced "cabbage").
If the saphenous vein in the leg is to be used for the bypass, an incision is made in the leg and the vein is removed. The vein is located on the inside of the leg. It runs from the ankle to the groin. The saphenous vein normally does only about 10 percent of the work of circulating blood from the leg back to the heart. Therefore, it can be taken out without harming you or your leg.
The internal mammary artery (IMA) can also be used as the graft. This has the advantage of staying open for many more years than the vein grafts, but there are some situations in which it cannot be used. The left IMA, or LIMA, is an artery that runs next to the sternum on the inside of the chest wall. It can be disconnected from the chest wall without affecting the blood supply to the chest. It is commonly connected to the artery on the heart that supplies most of the muscle.
Other arteries are also now being used in bypass surgery. The most common of these is the radial artery. This is one of the two arteries that supply the hand with blood. It can usually be removed from the arm without affecting the blood supply to the hand.
This illustration of a heart with grafting shows one saphenous vein (from the leg) and one internal mammary artery graft (from the chest).