The information below describes traditional coronary artery bypass graft surgery, which uses a heart-lung bypass machine to allow the surgeon to perform the procedure on a still heart. For more on minimally invasive procedures with smaller incisions or without the use of a heart-lung bypass machine, click here.

Traditional Coronary Artery Bypass Graft (CABG) Surgery

Just before your procedure, a member of the operating room team will prepare you for surgery. At this time, you will be in the preoperative (“preop”) room, an area separate from the operating room where you will change into a hospital gown and remove personal items such as jewelry, contact lenses, or dentures that should not be worn during the surgery. You will talk with your anesthesiologist in this room to discuss the plan for the medications that will put you “asleep” during the surgery. Your anesthesiologist may begin to administer medications through IV (intravenous) tubes while you are in the preoperative room.

From the preoperative room, you will be transferred to the operating room. While you are in the operating room, IV tubes will be used to deliver the medication that will put you to sleep, as well as to monitor blood pressure and the pressure in your heart chambers. After you are asleep, but before the operation begins, you will have a breathing tube inserted in your mouth or nose. 

Coronary bypass surgery is an open-chest procedure that is performed by a cardiac surgeon. Your surgeon will cut an incision in the middle of your chest that is 6–8 inches long. He or she will then divide your chest bone and open your rib cage to access your heart muscle.

You will be given medications to stop your heart from beating, so that your surgery can be performed on a still heart. The function of the heart and lungs will be taken over by a heart-lung bypass machine, so your brain and other organs and tissues will continue to receive the oxygen-rich blood that is critical for survival. 

Your heart surgeon will remove a blood vessel from one of several sites in the body to use as the bypass graft. The most successful bypasses use the internal mammary artery—the artery that runs just inside the edge of each side of the breastbone. During bypass surgery, the end of this blood vessel is removed from the chest wall to be used to attach to the heart beyond the blockage. The beginning of the internal mammary artery is left in place beneath the collarbone. In this way, blood flowing in the normal route up toward the collarbone flows down the internal mammary artery normally, except now it is joined to the coronary artery of the heart.  

The surgeon may also remove a segment of blood vessel from the leg (saphenous vein) or wrist (radial artery). The surgeon will then attach this new blood vessel (the graft) to the aorta (the major artery originating from the heart). The other end of the graft is attached to the coronary artery below the blockage that is being treated. The graft allows blood to flow from the aorta, down the graft to bypass the blockage, restoring blood flow to the heart muscle.

When the graft is in place, the heart-lung bypass machine will no longer take over the function of those organs, and your heartbeat will be restarted. Your heart surgeon will wire the chest bone closed and close up the incision in your chest with stitches or staples.

A bypass procedure typically takes 3–6 hours. In most cases the patient will be moved to an intensive care unit (ICU) after the procedure.

When you wake up after your surgery, you will have a breathing tube, as well as tubes for other functions. Click here to find out what to expect when you first wake up and during the first days of your recovery.

For more information on different types of coronary artery bypass graft surgery, read Evolution and Types of Coronary Bypass Surgery. While traditional coronary artery bypass graft surgery with a heart-lung bypass machine is still most common, newer techniques allow for surgery while the heart is still beating and for a much smaller incision in some cases.