Heart-lung machine

The invention: The first artificial device to oxygenate and circulate blood during surgery, the heart-lung machine began the era of open-heart surgery. The people behind the invention: John H. Gibbon, Jr. (1903-1974), a cardiovascular surgeon Mary Hopkinson Gibbon (1905- ), a research technician Thomas J. Watson (1874-1956), chairman of the board of IBM T. L. Stokes and J. B. Flick, researchers in Gibbon’s laboratory Bernard J. Miller (1918- ), a cardiovascular surgeon and research associate Cecelia Bavolek, the first human to undergo open-heart surgery successfully using the heart-lung machine A Young Woman’s Death In the first half of the twentieth century, cardiovascular medicine had many triumphs. Effective anesthesia, antiseptic conditions, and antibiotics made surgery safer. Blood-typing, anti-clotting agents, and blood preservatives made blood transfusion practical. Cardiac catheterization (feeding a tube into the heart), electrocardiography, and fluoroscopy (visualizing living tissues with an X-ray machine) made the nonsurgical diagnosis of cardiovascular problems possible. As of 1950, however, there was no safe way to treat damage or defects within the heart. To make such a correction, this vital organ’s function had to be interrupted. The problem was to keep the body’s tissues alive while working on the heart. While some surgeons practiced so-called blind surgery, in which they inserted a finger into the heart through a small incision without observing what they were attempting to correct, others tried to reduce the body’s need for circulation by slowly chilling the patient until the heart stopped. Still other surgeons used “cross-circulation,” in which the patient’s circulation was connected to a donor’s circulation. All these approaches carried profound risks of hemorrhage, tissue damage, and death. In February of 1931, Gibbon witnessed the death of a young woman whose lung circulation was blocked by a blood clot. Because her blood could not pass through her lungs, she slowly lost consciousness from lack of oxygen. As he monitored her pulse and breathing, Gibbon thought about ways to circumvent the obstructed lungs and straining heart and provide the oxygen required. Because surgery to remove such a blood clot was often fatal, the woman’s surgeons operated only as a last resort. Though the surgery took only six and one-half minutes, she never regained consciousness. This experience prompted Gibbon to pursue what few people then considered a practical line of research: a way to circulate and oxygenate blood outside the body. A Woman’s Life Restored Gibbon began the project in earnest in 1934, when he returned to the laboratory of Edward D. Churchill at Massachusetts General Hospital for his second surgical research fellowship. He was assisted by Mary Hopkinson Gibbon. Together, they developed, using cats, a surgical technique for removing blood froma vein, supplying the blood with oxygen, and returning it to an artery using tubes inserted into the blood vessels. Their objective was to create a device that would keep the blood moving, spread it over a very thin layer to pick up oxygen efficiently and remove carbon dioxide, and avoid both clotting and damaging blood cells. In 1939, they reported that prolonged survival after heart-lung bypass was possible in experimental animals. WorldWar II (1939-1945) interrupted the progress of this work; it was resumed by Gibbon at Jefferson Medical College in 1944. Shortly thereafter, he attracted the interest of Thomas J.Watson, chairman of the board of the International Business Machines (IBM) Corporation, who provided the services of IBM’s experimental physics laboratory and model machine shop as well as the assistance of staff engineers. IBM constructed and modified two experimental machines over the next seven years, and IBM engineers contributed significantly to the evolution of a machine that would be practical in humans. Gibbon’s first attempt to use the pump-oxygenator in a human being was in a fifteen-month-old baby. This attempt failed, not because of a malfunction or a surgical mistake but because of a misdiagnosis. The child died following surgery because the real problem had not been corrected by the surgery. On May 6, 1953, the heart-lung machine was first used successfully on Cecelia Bavolek. In the six months before surgery, Bavolek had been hospitalized three times for symptoms of heart failure when she tried to engage in normal activity. While her circulation was connected to the heart-lung machine for forty-five minutes, the surgical team headed by Gibbon was able to close an opening between her atria and establish normal heart function. Two months later, an examination of the defect revealed that it was fully closed; Bavolek resumed a normal life. The age of open-heart surgery had begun. Consequences The heart-lung bypass technique alone could not make openheart surgery truly practical. When it was possible to keep tissues alive by diverting blood around the heart and oxygenating it, other questions already under investigation became even more critical: how to prolong the survival of bloodless organs, how to measure oxygen and carbon dioxide levels in the blood, and how to prolong anesthesia during complicated surgery. Thus, following the first successful use of the heart-lung machine, surgeons continued to refine the methods of open-heart surgery. The heart-lung apparatus set the stage for the advent of “replacement parts” for many types of cardiovascular problems. Cardiac valve replacement was first successfully accomplished in 1960 by placing an artificial ball valve between the left atrium and ventricle. In 1957, doctors performed the first coronary bypass surgery, grafting sections of a leg vein into the heart’s circulation system to divert blood around clogged coronary arteries. Likewise, the first successful heart transplant (1967) and the controversial Jarvik-7 artificial heart implantation (1982) required the ability to stop the heart and keep the body’s tissues alive during time-consuming and delicate surgical procedures. Gibbon’s heart-lung machine paved the way for all these developments.