Arteries carry blood from the heart to the rest of the body. But sometimes
arteries become blocked. When this happens, surgeons create a new channel to
bypass the blockage. Doctors call it bypass graft surgery. It uses a working
blood vessel from another part of the body -- the graft -- to channel blood
around the blocked area.
When is bypass surgery needed?
The aorta is the main artery that carries blood from the heart. Two main
blood vessels branch from the base of it: the right and left coronary arteries.
Each of the coronary arteries has many branches.
When plaque buildup narrows an artery to about 70% of its normal size, the
artery is essentially blocked. Less severe blockage can be relieved by
angioplasty and stenting. That's when a tiny balloon is threaded into the
blocked artery and slowly inflated. Then a tube called a stent is used to keep
the artery open.
But severe blockage usually requires bypass surgery.
What is multiple bypass surgery?
Sometimes several arteries are blocked, and several bypasses are needed. If,
for example, there were blockages in all three coronary arteries and one
branch, a person would get four bypasses. This is called quadruple bypass
People who need several bypasses aren't necessarily at higher risk than
those who need just one, says UCLA professor Prediman K. Shah, MD, director of
cardiology and the Atherosclerosis Research Center
at Cedars-Sinai Medical Center in Los Angeles.
"It is not the number of bypasses that dictates a patient's risk," Shah
tells WebMD. "The risk is more dependent on the general condition of the
patient, whether the patient has other conditions, such as kidney disease or diabetes, and the condition of the heart muscle itself.
So if the patient's condition is good, the number of bypasses may mean a longer
surgery but not significantly greater risk."
How is bypass surgery done?
Doctors take a substitute blood vessel from another part of the body. It's
safe to do this because the body has other ways of getting blood to areas.
The surgeon then attaches one end of the graft to the aorta and the other
end to the coronary artery below the blockage.
The traditional operation calls for a six- to eight-inch cut down the center
of the breastbone so the surgeon can get directly at the heart. During the
operation, the body is connected to a heart-lung bypass machine that keeps the
blood flowing. The heart is stopped while the doctor operates. Then the surgeon
uses special wires to close the chest.
Sometimes it's possible for the surgeon to use minimally invasive surgical
techniques. In this case, the incision is much smaller. And in some cases, the
heart does not even have to be stopped. However, these techniques can't be used
for all bypass surgeries.