In a world-first, US surgeons have successfully transferred a kidney taken from a pig into a braindead human patient, in a major step towards using animal organs in human transplantations.

The team at NYU Langone Health performed the operation on a woman who was recently declared braindead, with the permission of her family. The sole object of the study, according to the lead surgeon Dr Robert Montgomery, was “to provide the first evidence that what appears to be promising results from non-human primates will translate into a good outcome in a human.”

One major obstacle in making xenotransplantation possible has been the rejection of organs by hosts. To overcome this, the team used an organ from a pig that had been genetically engineered in order to remove a sugar molecule known to play a significant role in rejection. The surgeons attached the kidney to large blood vessels outside of the recipient and monitored it for two days.