LOMA LINDA, Calif. -- In a series of experiments in lambs and goats that seems straight out of science fiction, surgeons at Loma Linda University Medical Center have "reanimated" hearts that have sat lifeless within dead animals for as long as 45 minutes and successfully transplanted them into other animals.
The researchers say that these preliminary findings, if confirmed and deemed ethically and legally acceptable for tests in humans, could dramatically expand the supply of human hearts for organ transplants. Because of an extreme shortage of organs, more than a quarter of the 2,400 Americans awaiting heart transplants are likely to die before a heart becomes available.
With a combination of drugs and other manipulations, the scientists have successfully reanimated and then transplanted hearts more than 20 times, said Dr. Steven R. Gundry, a heart surgeon and the leader of the research team.
"We really hope that if this continues to work, there can be a real use of donors that are being absolutely wasted now," Mr. Gundry said in an interview. "There is a lot of disbelief among other surgeons but at the same time a lot of excitement."
Currently, hearts for transplantation are removed from individuals who are pronounced brain dead, while they are LTC maintained on a respirator and their hearts continue to beat. The continued circulation of blood prevents the heart from deteriorating. The typical organ donor is an otherwise healthy individual who dies from a motor vehicle accident, head trauma, a gun shot or stabbing, or sudden bleeding into the brain.
But in the current system of organ procurement, many potential donors who die in these ways are never identified. In other instances, family members decline to authorize organ donation.
While the demand for heart and other transplants is growing, the number of organs obtained from cadavers has leveled off. In 1991, there were 2,127 heart transplants in the United States, about the same number as in 1990, according to the United Network for Organ Sharing in Richmond, Va.
The new approach raises the possibility of, with consent, procuring hearts from otherwise healthy individuals who die because their hearts stop beating; such hearts had not been considered usable. For example, such individuals might bleed to death, despite resuscitation in hospital emergency rooms.
Mr. Gundry said he had named the technique "reanimation," a term often associated in the public mind with scientific fantasy, because it seemed to offer the best description of the research.
In an interview, Mr. Gundry said that heart surgeons have believed for many years that the heart muscle suffers irreversible damage at normal temperature if it is deprived of blood and oxygen for 15 minutes or more. His research team and others, however, have found that the true damage is less than was feared.
In the first report of the ongoing research, being published in the May issue of the Annals of Thoracic Surgery, Gundry and his colleagues described the successful "reanimation" and transplant of four "dead" hearts from juvenile lambs.
The report said the hearts were harvested after the animals, who had been anesthetized, were allowed to bleed to death in a manner that simulated a failed resuscitation attempt in an emergency room.