When you need a new liver, it's a matter of life and death. While some people can receive part of a liver from a living donor match (the liver is part of the body that can regenerate, but the procedure is still very difficult), most people who need new livers have to be placed on a waiting list for an organ donor liver to become available from a cadaver. When a liver is in the right place at the right time, it goes to the person at the top of the list.
However, you run into problems when the person who needs to receive a liver is a baby or a child. After all, they can't fit a full adult sized liver. Instead, babies and children on the wait list receive a part of a liver, which then will hopefully grow once it's inside. But where do you get liver PARTS? Most adults who are on a liver list will be given a whole liver. And most children and babies who are on a liver list...will also get a whole liver. They will get the part they need and the rest will not be used.
But it turns out, adult liver recipients may not NEED a whole liver to function. And if you can split a liver, you can save two lives instead of one.
Doyle et al. "Outcomes with Split Liver Transplantation Are Equivalent to Those with Whole Organ Transplantation" Journal of the American College of Surgeons, 2013.
(A liver. Source)
Split liver grafts aren't unknown. Usually the smaller part goes to the child and the larger to an adult. But when people first started doing it in the late 1980's, the results...weren't so good. But since the 1990's, people started having more success. But splitting livers still wasn't considered a viable option. What was needed was a study to convince people that splitting livers was safe.
The authors of this study did a retrospective analysis at a single transplant center. Of the over 1000 people who had received liver transplants, only 4.2% got a split liver. But for those who did...well it worked! It worked just as well as getting a whole liver transplant, both in adults and in children.
This is great news. Relatively few people need liver transplants, but splitting livers could ensure that the people who do it one, get one. By splitting just 80 more livers per year, for example, it would be possible to take care of every small child on the waitlist (caveats being getting them the liver, paying the costs, etc). With results just like those of whole livers, I hope that people won't wait. Saving two people with one organ is just too good to lose.