Coronary arteries are the blood vessels which supply the muscle of the
heart with its oxygen and energy supply. Coronary arteries can become
blocked by the build-up of a fatty substance in the wall of the coronary
artery. When the blockage is severe, it produces chest pain during exercise
and can produce a heart attack when some of the heart muscle dies.
Coronary artery disease is very common in the UK. More than half of all
the heart operations carried out each year are for coronary artery disease.
In coronary artery surgery procedures a bypass graft is carried out
which allows the blood to flow from the aorta, the main blood vessel out of
the heart, into the coronary artery beyond the site of the blockage. A bypass
graft is created for each of the main coronary arteries affected by coronary
artery disease. In some patients this will involve only a single graft to one
affected artery. More commonly, two, three or four grafts are necessary.
The surgeon uses another blood vessel from the patient’s own body to
create the graft. Most often this is a vein removed from the leg. The leg
vein which lies just underneath the skin may be removed safely without
interfering with the health of the leg. In some patients, perhaps because of
varicose vein problems in previous years, leg vein may not be suitable. It is
then possible to use vein from the arm.
In the last few years, it has become apparent that an artery which runs
inside the chest wall, known as the internal mammary artery, can be used to
create bypass grafts in coronary artery disease patients. Most surgeons now
believe that, when possible, this artery should be used, especially in younger
patients, since the use of the artery graft gives excellent long-term results.
Coronary artery surgery procedures are, as with valve operations,
carried out through the same chest incision, using heart/lung bypass during
the operation.