Doctors at the University of Maryland Medical Centre have, for the first time, succeeded in transplanting the heart of a genetically modified pig into the human body without immediate rejection.
Doctors transplanted the pig heart into a patient in a last-ditch effort to save his life and the hospital said on Monday that the patient was doing well three days after the highly experimental surgery.
While it's too soon to know if the operation really will work, it marks a step in the decades-long quest to one day use animal organs for life-saving transplants. Doctors at the University of Maryland Medical Center say the transplant showed that a heart from a genetically modified animal can function in the human body without immediate rejection.
The patient, David Bennett, a 57-year-old Maryland handyman, knew there was no guarantee the experiment would work but he was dying, ineligible for a human heart transplant and had no other option, The Associated Press quoted his son as saying.
It was either die or do this transplant. I want to live. I know it's a shot in the dark, but it's my last choice, Bennett said a day before the surgery, according to a statement provided by the University of Maryland School of Medicine.
On Monday, Bennett was breathing on his own while still connected to a heart-lung machine to help his new heart. The next few weeks will be critical as Bennett recovers from the surgery and doctors carefully monitor how his heart is faring.
There's a huge shortage of human organs donated for transplant, driving scientists to try to figure out how to use animal organs instead. Last year, there were just over 3,800 heart transplants in the US, a record number, according to the United Network for Organ Sharing, which oversees the nation's transplant system.
"If this works, there will be an endless supply of these organs for patients who are suffering, said Dr. Muhammad Mohiuddin, scientific director of the Maryland university's animal-to-human transplant programme.
Earlier attempts at such transplants or xenotransplantation have failed, largely because patients' bodies rapidly rejected the animal organ. Notably, in 1984, Baby Fae, a dying infant, lived 21 days with a baboon heart.
The difference this time: The Maryland surgeons harvested the heart from a genetically modified pig which was devoid of a sugar in its cells that's responsible for hyper-fast organ rejection. Several biotech companies are developing pig organs for human transplant; the one used for Friday's operation came from Revivicor, a subsidiary of United Therapeutics.