Surgeons at University of Pennsylvania attached modified organ from pig to brain-dead human body

Surgeons externally attached a pig liver to a brain-dead human body and watched it successfully filter blood, a step toward eventually trying the technique in patients with liver failure.

The University of Pennsylvania announced the novel experiment on Thursday, a different spin on animal-to-human organ transplants. In this case, the pig liver was used outside the donated body, not inside – a way to create a “bridge” to support failing livers by doing the organ’s blood-cleansing work externally, much like dialysis for failing kidneys.

Animal-to-human transplants, called xenotransplants, have failed for decades because people’s immune systems rejected the foreign tissue. Now scientists are trying again with pigs whose organs have been genetically modified to be more humanlike.