Medicine by Design: The Practice and Promise of Biomedical Engineering

CHAPTER 4. The Pump and Its Pipes

Chapter 4 The Pump and Its Pipes The research taking place at the University of Virginia’s Biomedical Engineering Department is a testament to how far cardiovascular medicine has progressed in the past half century. Just before I was born, in 1952, physicians treated my ailing grandfather, who had high blood pressure and atherosclerosis, by placing him on a rice and honey diet. He died at age 51 of a massive stroke. Such was the woefully meager assortment of tools in physicians’ and surgeons’ bags in the mid-twentieth century, an era in which there were no cardiac pacemakers, no defibrillators, no arterial stents, no ventricular assist devices, no coronary artery bypass operations, very few effective cardiac drugs, and only the crudest of open-heart surgeries. If you had a serious cardiovascular condition in 1950, your prospects were only marginally better than they would have been in 1650. All that began to change rapidly in the 1950s and 1960s, when an explosion in technology—driven, in part, by the invention of the transistor and the computer—led to a succession of inventions that dramatically increased the survival of people with ailing hearts. A crucial advance was the invention of the machine that took over the functions of the heart and lungs in the operating room, ushering in the era of open-heart surgery. The inventor was Philadelphia surgeon John Gibbon, who first used the machine on a patient in 1953 after twenty years of experimentation, sometimes using stray cats.
46 MEDICINE BY DESIGN In 1957, Minnesota cardiac surgeon C. Walton Lillehei used the first externally powered pacemaker to treat a heart arrhythmia in a child. In 1958, Swedish surgeons placed the first implantable pacemaker in a patient. Two years later, an electrical engineer from Buffalo , New York, Wilson Greatbatch, employed two silicon transistors to create the first implantable pacemaker in the United States. Minnesota engineer Earl Bakken, working with Lillehei, played an important role in developing the first battery-powered pacemakers. Bakken formed a company, Medtronic, that is now the world’s largest biomedical engineering firm, with annual sales of $9 billion and a workforce of 32,000 people worldwide. In 1966,Houston heart surgeon Michael E.DeBakey implanted the first left ventricular assist device in a patient. The pump supported a woman for sixteen days until her own heart could fully resume pumping after valve repair surgery. In 1967, South African heart surgeon Christiaan Barnard performed the first human heart transplant. The patient lived eighteen days. That same year, the first coronary artery bypass surgery was performed at the Cleveland Clinic. In 1977, a Swiss physician performed the first angioplasty, giving birth to a procedure in which arterial plaque buildups are compressed using a balloon-like device inserted through a vessel in the groin. In 1982, the first artificial human heart—designed by Dr. Robert K. Jarvik— was implanted in patient Barney Clark. He lived 112 days. In 1987, doctors implanted the first arterial stents—scaffold-like devices that help keep arteries open after angioplasty. Today, most of these procedures have become routine, helping prolong the lives of millions of people who might otherwise have had heart attacks, strokes, heart failure, or fatal cardiac arrhythmias. More than 2 million people worldwide now have cardiac pacemakers , with cardiologists implanting about 175,000 pacemakers annually in the United States. Doctors perform 2 million angioplasty procedures annually around the world, including 550,000 in America. Cardiologists in the United States perform about 500,000 coronary artery bypass operations a year and implant 800,000 stents. But as the case of Emswiler’s HeartMate pump shows, developing one of these lifesaving devices and bringing it to market can be a marathon journey. No one knows that better than Victor L. Poirier, the inventor of the HeartMate, the most widely used left ventricular assist device: it took twenty years and $62 million to develop the HeartMate and win approval from the U.S. Food and Drug Administration (FDA). In the late 1960s, when Poirier first began work on the project at the request of the federal government, a sizable number of engineers and surgeons dreamed of creating a total artificial heart. But Poirier and his team of engineers at Thermo Cardiosystems Inc. soon deduced that creating an entire heart, with four separate chambers, would be a massive undertaking. Like good engineers, they broke the task into manageable pieces. Knowing that the left...