<P> Dr. Wilfred G. Bigelow of the University of Toronto found that such procedures could be performed better in a bloodless and motionless environment . Therefore, during open heart surgery, the heart is temporarily stopped, and the patient is placed on cardiopulmonary bypass, meaning a machine pumps their blood and oxygen . Because the machine cannot function the same way as the heart, surgeons try to minimize the time a patient spends on it . </P> <P> Cardiopulmonary bypass was developed after surgeons realized the limitations of hypothermia in cardiac surgery: Complex intracardiac repairs take time, and the patient needs blood flow to the body (particularly to the brain), as well as heart and lung function . In 1953, Dr. John Heysham Gibbon of Jefferson Medical School in Philadelphia reported the first successful use of extracorporeal circulation by means of an oxygenator, but he abandoned the method after subsequent failures . In 1954, Dr. Lillehei performed a series of successful operations with the controlled cross-circulation technique, in which the patient's mother or father was used as a "heart - lung machine". Dr. John W. Kirklin at the Mayo Clinic was the first to use a Gibbon - type pump - oxygenator . </P> <P> Nazih Zuhdi performed the first total intentional hemodilution open heart surgery on Terry Gene Nix, age 7, on 25 February 1960 at Mercy Hospital in Oklahoma City . The operation was a success; however, Nix died three years later . In March 1961, Zuhdi, Carey, and Greer performed open heart surgery on a child, age 3 ⁄, using the total intentional hemodilution machine . </P> <P> In the early 1990s, surgeons began to perform off - pump coronary artery bypass, done without cardiopulmonary bypass . In these operations, the heart continues beating during surgery, but is stabilized to provide an almost still work area in which to connect a conduit vessel that bypasses a blockage using a technique known as endoscopic vessel harvesting (EVH). </P>

When was the first open heart bypass surgery performed