Late in 2007 I found myself riveted by a case playing out at the University of California, Los Angeles, the medical center where I trained and had once worked as a transplant surgeon. A 17-year-old girl named Nataline Sarkisyan was in desperate need of a transplant after receiving aggressive treatment that cured her recurrent leukemia but caused her liver to fail. Without a new organ, she would die in a matter of a days; with one, she had a 65 percent chance of surviving. Her doctors placed her on the liver transplant waiting list.

Nataline’s case was not all that different from the more than 200 liver patients I had seen successfully transplanted every year at that institution. She was critically ill, as close to death as one could possibly be while technically still alive, and her fate was inextricably linked to another’s. Somewhere, someone with a compatible organ had to die in time for Nataline to live.

But even when the perfect liver became available a few days after she was put on the list, doctors could not operate. What made Nataline different from most transplant patients, and what eventually brought her case to the attention of much of the country, […]