A first-ever experiment shows how pigs might one day help people who have liver failure

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 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.