For many years, major heart surgery—opening the chest to operate directly on an exposed heart--was considered outside the realm of possibility. The heart would cease beating during such operations. How could patients survive? A few pioneers did perform emergency surgery directly on the open heart, one of the first being African-American surgeon Daniel Hale Williams, who opened the chest of a stabbing victim and sewed up the pericardium (the sac surrounding the heart) in 1893. Both Ludwig Rehn (1849-1930) and Forina sutured heart wounds 1896. More lengthy and complicated heart operations, however, required a way to keep the blood oxygenated and circulating while a patient's heart was undergoing the operation. American surgeon, John H. Gibbon, Jr., devoted himself to solving this problem in the 1930s. Assisted by his wife Mary, Gibbon persisted until he had developed a workable pump-oxygenator, or heart-lung machine, that shunted blood from...