Doctors are years from transplanting animal organs into people, but at least five operations in which humans were connected to pig livers via filtering lines have been quietly conducted in the United States during the last two years, transplant experts said Thursday.
In what doctors call "ex vivo," or outside-the-body, procedures, swine livers saved ailing patients while their organs recovered from medication poisoning or sustained patients who needed a viable bridge until a transplantable human liver was found.
The procedures were approved on a compassionate basis by the Food and Drug Administration despite concerns that pigs naturally harbor a potentially transmissible retrovirus. And at least during the last year a loose moratorium on xenotransplantation--putting animal organs and tissue in humans--has been in effect.
"What we were trying to do is buy the patients some time," said Dr. Amy Patterson of the FDA.
The patients, who were not identified, fared well, Patterson said.