Coronary artery bypass surgery, or CABG, is a procedure which takes a blood vessel from somewhere else in the body and uses it to bypass a vessel in the heart that has been damaged and blocked. This improves the blood supply to the heart and in turn improves the delivery of oxygen and nutrients to the heart muscle.
After the anesthesia takes effect the surgical area will be scrubbed with a special disinfectant soap and may also be shaved. The surgeon will then make a 6 to 8 inch incision down the middle of the chest. The breastbone is then separated, the heart sac is carefully pulled back, and the heart is examined. At this point the doctor will remove the necessary graft vessels for the artery bypass. Most commonly an artery from the chest, called the "mammary artery", and/or a vein from the leg are used. However, an artery from the arm or wrist may also be used. Once this is done, the bypass procedure can continue.
At this point the heart will need to be cooled to keep it still. At this time the heart will be connected to the heart/lung bypass machine. After giving a large dose of a blood-thinning medicine called Heparin, to make sure that the blood does not clot, the surgeon will connect the heart to the heart/lung bypass machine with a plastic tube. Blood from the heart is then sent to the bypass machine through this tube. The machine supplies the blood with oxygen and then pumps it back to the rest of the body through the other tube. While connected, the blood simply bypasses the heart and lungs, but still reaches the rest of the body.
After being connected to the heart/lung bypass machine, each of the blocked coronary arteries will be carefully inspected. The surgeon will determine the ideal place to attach the new vessel or vessels. Usually the vessel is sown into an area below the blockage and then into a location in the aorta. When your heart resumes its normal function and can support your body with its own pumping ability it will slowly be removed from the heart/lung bypass machine. Because everyone's heart is different, the time it takes to be removed from the bypass machine varies.
If your heart is slow to return to its normal function, several options are available to help it regain strength. These include medication through your IV or electrical stimulation from small, thin wires, called "pacing wires", to help your heart beat normally until your own heart's electrical system has recovered. These wires are placed directly onto the surface of your heart and will be left inside your chest during your hospital recovery. Usually these are temporary and should be removed prior to your going home. But in some patients the wires may need to be replaced by a permanent pacemaker. Several chest tubes will be also be placed inside the chest to collect any fluid that drains into the spaces around the heart and lungs. These help to insure that the lungs and heart are working properly.
Lastly, the breastbone is brought back together with thick steel wire. This helps the breastbone to heal and prevents movement. The skin incision is then closed with stitches and a sterile bandage is applied.