Heart pumps blood oxygenated from the lungs to different tissues of body. The oxygen supplied through the blood is necessary for the proper growth and functioning of the tissues. If blood flow is stopped at normal body temperature, permanent brain damage normally occurs in three to four minutes — death may follow shortly afterward.
During cardiac surgeries, especially those involving opening up of chambers of heart, functions of the heart and lung, has to be bypassed to an artificial device for maintaining the circulation of blood and the oxygen content of the body. This device is commonly termed as Heart Lung Machine or cardiopulmonary bypass machine. The first successful open heart procedure on a human utilising the heart lung machine was performed by John Heysham Gibbon on May 6, 1953.
Cardiopulmonary bypass consists of two main functional units, the pump and the oxygenator which removes oxygen-deprived blood from a patient’s body and replace it with oxygen-rich blood. Heart Lung Machine is often used in:
- Coronary artery bypass surgery
- Repair of large septal defects(atrial septal defect, ventricular septal defect, atrioventricular septal defect)
- Cardiac valve repair and/or replacement(aortic valve, mitral valve, tricuspid valve, pulmonic valve)
- Repair of some large aneurysms(aortic aneurysms, cerebral aneurysms)
- Repair and/or palliation of Congenital Heart Disease (tetralogy of fallot, transposition of the great vessels)
- Transplantation (heart transplantation, lung transplantation, heart-lung transplantation)