Extracorporeal circulation is a medical technique that temporarily takes over the function of the heart and lungs during certain surgical procedures. It involves diverting blood from the body to a machine, known as a heart-lung machine, which oxygenates the blood and removes carbon dioxide before returning it to the body. This allows surgeons to operate on the heart or lungs without the complications of blood flow. This method is commonly used in cardiac surgery, such as coronary artery bypass grafting or heart valve repairs. By maintaining blood circulation and oxygenation, extracorporeal circulation helps ensure that vital organs remain functional while the surgical team works on the heart or lungs.