HEART SURGERY: THE ARTIFICIAL HEART

Early Attempts

Heart donors are scarce, and recipients often do not have the luxury of time. To facilitate the process of heart transplantation, there was a concerted effort during the 1960s to develop an artificial heart for temporary use in bridging the time gap between a patient's need and the availability of a donor or as an assisting device for people whose hearts are not fully functional. Early experiments involved the use of a plastic banana-shaped device with internal valves to assist the blood in its movement from one heart chamber to another. A large pump outside the body provided the force. Dr. Michael E. DeBakey used such a device, which he called an intrathoracic pump, on a forty-two-year-old patient in 1963, but the patient died four days later, and there was some indication that the pump had caused blood clots.

An Improved Model

Dr. Adrian Kantrowitz of Brooklyn's Maimonides Hospital codeveloped the heart booster produced by the Avco-Everett Research Laboratory near Boston, where his physicist brother, Dr. Arthur Kantrowitz, was director. Their device, a banana-shaped booster without valves, attacked the common problem of blood clots experienced with early heart pumps. The Kantrowitz device was meant to be implanted permanently in patients with severe heart failure. It could be placed in the chest cavity and attached without open-heart surgery. The pump was intended to be turned on only when needed. The first Kantrowitz pump was implanted on 4 February in a patient who died within twenty-four hours. A second operation was more successful: the patient died of a stroke twelve days after the operation, but the pump operated properly.

Temporary Heart

In August 1966 DeBakey implanted a pump developed for a different use than the Kantrowitz device. DeBakey's pump provided temporary assistance to hearts with diseased valves and other irregularities that could be addressed surgically. It assisted the left ventricle, the chamber of the heart that pumps reoxygenated blood to the body. The DeBakey pump was first used on a rheumatic-fever victim who required valve replacements. It was successful, and the patient was re-leased from the hospital a month after her operation.

Dispute between Colleagues

The first complete artificial heart was placed by Dr. Denton A. Cooley on 4 April 1969 in patient Haskell Karp at Baylor University Hospital. Cooley, a colleague of DeBakey, had done more heart transplants than any other surgeon in 1969, when he operated on Karp. While DeBakey and Cooley appeared to get along well in public, they were increasingly at odds with each other in private. Karp's case led to a public break between them over an issue related to the artificial heart.

No Donor

Karp was a forty-seven-year-old dying of heart failure. His condition quickly deteriorating, Cooley tried to remove the damaged part of the heart and repair it with a Dacron graft. When Karp's heart stopped beating, Cooley removed the heart completely and put the patient on a heart-lung machine, a process that could be maintained only for a limited time.

Emergency Measures

Dr. Domingo Liotta, a colleague of Cooley's at Baylor, had been working with DeBakey on an artificial heart for ten years. His present model was ready to try, and Liotta suggested it might keep Karp alive for one or two weeks while he was waiting for a donor. The artificial heart was about the size of a real heart and made of Silastic, a silicone plastic. It had Dacron cuffs to attach to the blood vessels, and an external pump the size of a refrigerator was the power source, attached by hoses through the chest wall. Cooley in-stalled the DeBakey-Liotta artificial heart in Karp. During the sixty-five hours he was on the pump, Karp re-gained consciousness and was even able to speak. On the basis of a national televised appeal, a donor was found, but Karp died of pneumonia and kidney failure thirty hours after the heart transplant.

Stolen Idea?

DeBakey felt Cooley had stolen his idea and ten years of research. He thought Karp was a poor candidate for an artificial heart and that Cooley should have consulted him before using it. Cooley apparently felt he had to do something for Karp, and the artificial heart was his only choice. He felt DeBakey was primarily concerned because Cooley received credit for implanting the first artificial heart. As a result of the dispute, Cooley resigned from Baylor to associate with the University of Texas at Houston and form the Texas Heart Institute.

STAPLE 'EM

Surgical sewing, or suturing, is a slow and tedious process. The technique of surgical sewing has been used in one way or another since ancient times, but it had never been automated until the autostapler was marketed in the mid 1960s.

U.S. Surgical Corporation made the original instrument, which was a monkey wrench with a gun trigger. Disposable cartridges could be placed in the instrument with different sizes of suture placed in different patterns depending on the cartridge chosen. When the autostapler was placed against a patient's skin and the trigger was pulled, it placed a series of tiny metal staples about three to four inches across at a time, closing the incision. The staples were made of stainless steel, nonreactive in human tissue.

Dr. Mark Ravitch of the University of Chicago School of Medicine was one of the first to develop an operation for the instrument itself. He used staples across the biggest vein returning blood to the heart (the vena cava) to prevent clots in the legs from getting into the lungs.

Sources:

"An Act of Desperation," Time, 93 (18 April 1969): 58;

"An Artificial Heart," Time, 93 (11 April 1969): 46;

C. P. Gilmore, "Booster Pump Gives New Life to Failing Hearts," Popular Science, 187 (December 1965): 48-51, 194;

"Half-Heart Replacement," Time, 82 (8 November 1963): 50;

"The Most Important Operation in History," Science Digest, 60 (July 1966): 46-49.