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How a low-tech invention changed the course of medicine

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Dr. Walt Lillehei with a 1955 display that demonstrates how the bubble oxygenator works.

With about $15 worth of odds and ends from their laboratory -- including tubing made for carrying beer -- two University of Minnesota medical legends ended the era when a serious heart defect meant a drastically shortened life.

Richard DeWall and Walt Lillehei in 1955 created what became known as the DeWall-Lillehei bubble oxygenator, the very first artificial heart-lung machine. The machine worked by extracting depleted blood from the patient and feeding it with oxygen bubbles shot in through a series of needles. The rejuvenated blood was then mixed with an anti-foaming agent and channeled back into the circulatory system.

The bubble oxygenator replaced two riskier alternatives available to open-heart surgeons at that time. One was induced hypothermia. When Lillehei and another University surgeon, John Lewis, performed the world's first open-heart surgery in 1952, they lowered their patient's body temperature to 80 degrees to slow her metabolism. The surgery was a success, but hypothermia gave doctors only a brief window -- about 10 minutes -- to operate.

Dr. Richard DeWall with the heart-lung machine in 1956.

The other early alternative was to have a live donor (sometimes a parent of the patient) in the operating room serving as the patient's heart and lungs during the procedure. But "cross-circulation" was risky to the donor, and finding the right blood-type match could be difficult.

While other heart-lung devices were being tested at the time, the bubble oxygenator stood out. It was easy to sterilize and, unlike other prototypes, contained no moving parts which could break down. It was the prototype of equipment still in use today. It has allowed trained cardiac surgeons in any modern, well-equipped hospital to perform open-heart surgery. According to the American Heart Association, about 665,000 open-heart surgeries were performed in the United States in 2003.

The DeWall-Lillehei bubble oxygenator is just one in a long line of medical breakthroughs at the University that have saved people's lives. Lillehei himself, who earned the nickname the "father of open-heart surgery," also invented the world's first artificial heart valve and collaborated with Earl Bakken on the first battery-powered pacemaker.

Further reading

University of Minnesota Medical Milestones

Earl Bakken: The man who created an industry