LOS ANGELES -- In an unprecedented procedure, researchers at Cedars-Sinai Medical Center transplanted a pig's liver into a dying woman in an unsuccessful effort to keep her alive until she could receive a donated human liver.
The patient, identified by hospital officials as Susan Fowler, 26, of Burbank, Calif., was being rushed back into surgery late yesterday to replace the animal organ with a human liver, a hospital spokesman said, but she took a turn for the worse and died just before going into surgery.
The effort by the Cedars-Sinai surgeons to save the young woman's life was believed to be the world's first such use of a pig's liver.
It followed similarly historic surgery last June at the University of Pittsburgh Medical Center involving the first use of a baboon liver in a human.
The recipient of that organ, a 35-year-old man whose liver had been damaged by the hepatitis B virus, lived 71 days, then died Sept. 6 of a massive stroke.
Ms. Fowler, a liver disease sufferer since childhood, was comatose and hours from death when she arrived by helicopter at the hospital before dawn Sunday, according to Mr. Wise.
She did not regain consciousness before the second transplant operation.
"We are making fresh footprints in the snow," Mr. Wise said. "It is hard to say what is going to happen because it has never been done before."
Unusual secrecy surrounded the first operation, which involved "piggy-backing" the pig liver onto Ms. Fowler's failing liver to take over its blood cleansing and metabolizing function.
The eight-hour surgery took place early Sunday, but was not announced by Cedars-Sinai until yesterday.
Mr. Wise declined to identify the six surgeons in the operation, saying they were tending to the patient and were concerned about protecting her privacy.
Nevertheless, the surgical team on both the pig liver transplant and the human liver transplant was widely believed to have been headed by Leonard Makowka. He is chief of transplant surgery at Cedars-Sinai, a leading researcher in liver transplants and a protege of transplant pioneer Thomas E. Starzl, who directed the baboon liver transplant in Pittsburgh.
Pig livers have been studied for some time as temporary replacements for a failed human liver, largely because of their anatomical similarity to the human organ.
"Its size is comparable, unlike the baboon's which is very small," explained Dr. Ronald W. Busuttil, director of the liver transplant program at the University of California, Los Angeles. "The vessel hookups and the bile duct hookups are also very comparable to what we seen in the human."
However, because pigs are so dissimilar to humans in other respects, such a transplant has little chance of surviving more than a few days, Dr. Busuttil said.
"It is a temporizing measure, and probably temporizing for only a day or two," he said, contrasting it with the longer-term success achieved in Pittsburgh with the baboon liver transplant.
Dr. Busuttil said pigs are also attractive as donors because they are not an endangered species, and their use for this purpose might be less objectionable to ethicists and animal rights activists.