What is Bypass Surgery?

Bypass surgery of the heart is other wise known as a coronary artery bypass graft (CABG).  Coronary arteries are the small blood vessels that supply the heart muscle with oxygen and nutrients.  This surgery is performed when these small arteries become so clogged with plaque (which is a build-up of fat and cholesterol) that it is effectively preventing oxygen enriched blood from reaching the heart.  This is called ischemic heart disease or coronary artery disease (CAD). It can cause chest pain or angina.

Sometimes CAD does not cause pain until the blood supply to the heart becomes critically low, and the muscle begins to die. The first symptom of CAD in this case may be a potentially deadly heart attack. Symptomless CAD is especially common in diabetics.

How is the surgery performed:
After the patient is anesthetized and completely free from pain, the heart surgeon makes an incision in the middle of the chest and separates the breastbone.

Through this incision, the surgeon can see the heart and aorta (the main blood vessel leading from the heart to the rest of the body).  Often a vein from the leg called the saphenous vein is to be used for the bypass, an incision is made in the leg and the vein removed. After surgery, the breastbone will be rejoined with wire and the incision will be sewn closed.

In the traditional surgery, the patient is connected to the heart-lung machine, or bypass pump, which adds oxygen to the blood and circulates blood to other parts of the body during the surgery. This is necessary because the heart muscle must be stopped before the graft can be done.
 
However, many surgeons prefer to perform a beating heart surgery.  This has become a popular method because the heart never stops and a heart-lung machine isn't necessary. This is called off-pump coronary artery bypass or OPCAB.
 
Another alternative is the use of smaller incisions that avoid splitting the breastbone. This is referred to as Minimally Invasive Direct Coronary Artery Bypass or MIDCAB.

Coronary bypass surgery can now be performed with the aid of a robot, which allows the surgeon to perform the operation without even being in the same room as the patient.