Glossary of Terms
A procedure that diverts or reroutes the ordinary flow of blood. In heart surgery, bypass is most often used to describe two procedures or techniques: 1) Cardio-pulmonary bypass surgery, or 2) Coronary artery bypass surgery.
Cardio-pulmonary bypass surgery is a technique where a heart-lung machine is used to support a patient's heart and lung function during an open heart procedure. When cardio-pulmonary bypass is utilized, blood is drained from the body by a tube (cannula) that is usually placed in the right atrium, where all of the venous blood of the body is transported. The blood is drained to the heart-lung machine, which removes CO 2 , adds Oxygen, and then pumps the blood back to the patient, through plastic tubing from the heart-lung machine, usually into the patient's aorta. By removing the blood from the right atrium, the heart and the lungs are "bypassed". And by the heart-lung machine pumping blood back to the body, the heart is "bypassed". The other use of the word "bypass" in heart surgery refers to coronary artery bypass surgery. In this procedure, a vein or artery from the patient's body is used to construct an alternative pathway for blood to go around, or "bypass", a narrowing or blockage in the patient's coronary artery. Hence the name "coronary artery bypass".