To understand a triple bypass, it is essential to understand a few things about the anatomy of the heart and heart disease.
The blood vessels that supply the heart with its own blood supply, which are different than the vessels that supply the blood pumped by the heart, are called the coronary arteries. In some people, the coronary arteries become blocked, a condition known as coronary artery disease. If a blockage is severe, it can completely stop blood flow to the area of the heart that is fed by that particular blood vessel.
In many cases, coronary artery disease can be treated with medication, lifestyle changes and less invasive procedures. However, for some patients the blockage(s) are so severe that surgery is necessary to make sure the heart continues to receive adequate blood flow. This procedure is known as coronary artery bypass graft surgery (CABG).
During the procedure, blood vessels are taken from another area of the body, typically the leg, and grafted onto the existing heart vessel before and after the blockage. It is not unlike a quick detour your car takes to avoid an accident, with the blood literally being routed around the blocked vessel.
The number of vessels that are diseased typically dictates the number of grafts that will be performed. If three vessels are blocked and need to be bypassed, the surgery is referred to as a triple bypass because three grafts are performed. If two vessels are bypassed the surgery is called a double bypass, and so on.
Sources: What Is Coronary Artery Bypass Grafting? National Heart Lung and Blood Institute. Accessed 2009. http://www.nhlbi.nih.gov/health/dci/Diseases/cabg/cabg_whatis.html
