1.  Why do people sometimes need “by-pass” surgery?

 The tissue of the heart has its own supply of arteries and veins.  If the coronary arteries become clogged so that the heart muscle is not receiving an adequate supply of oxygen-rich blood, a condition called ischemia occurs.  The person may or may not be aware that it is occurring.  If tissue is deprived of oxygen for too long, the cells will die.  This prolonged blockage is known as a myocardial infarction or heart attack.

 If it is found that a person has blocked coronary arteries, he/she may be a candidate for a coronary bypass operation.  In this case, a healthy blood vessel will be “patched in” to carry blood from the left or right coronary artery (if available) to the portion of the heart muscle that lacks an adequate blood delivery.  Sometimes the great saphenous vein of the leg is a good candidate to use for the by-pass.  Often more than one of these by-pass route is necessary, as in a “triple by-pass” or a “quadruple by-pass”.