Aged just 42, Erosalyn Deveza was drifting toward death.
Her kidneys were barely functioning. She was constantly exhausted. She had vertigo and vomited frequently. She was tethered to a home dialysis machine for eight hours each night as she slept.
A kidney transplant was the only thing that could save her, but it was unlikely to happen in time. There is a severe shortage of kidneys from deceased donors in the US.
No one on Deveza's side of the family could provide an organ through a living donation, doctors said, because all were at risk for the same kidney disease. It was too dangerous to leave any of them with a single kidney. Other family and friends were not a match.
This is a story of a daughter's answer to her mother's illness, an idea so obvious yet so inventive that it had never happened before, and hasn't since.
It took four women, two computer scientists, teams of doctors and support staff, luck and uncommon selflessness to pull it off. Though it occurred nearly two years ago, few knew about the case until it was published in a medical journal last month.
Profoundly simple, it may one day change organ transplantation and save lives.
"She's just amazing, my daughter," Deveza said.
"We got showed up by a 19-year-old," said John Roberts, one of the transplant doctors involved. "She thought of it. I didn't."
To compensate for the shortage of organs from deceased donors, the concept of "live, paired kidney donation" has sprung up in the past 25 years. Healthy people can live with one kidney, allowing them to donate the other.
But if the donor and intended recipient have incompatible blood or tissue types, there can be no transplant. The way around that is for a donor to find a matching recipient, with the understanding that the recipient will find someone to provide a kidney for whomever the original donor designates. In that way, the kidneys are "paired." Transplant hospitals and others coordinate this process.
Sometimes, the search is widened, forming chains of kidney donors and recipients to ensure that everyone who needs an organ receives one. The University of Alabama at Birmingham School of Medicine claims the nation's longest kidney chain at any single site, with 113 transplants performed over six years.
Nearly 6600 kidneys have been transplanted in pairs or chains, including 938 in 2018, according to the United Network for Organ Sharing, which coordinates the US transplant system.
Live donation works for livers too. Unlike most organs, livers grow back. If conditions are right, donors can give one lobe of their liver to a recipient whose liver is failing. Within a few months, both pieces should grow intofully functioning livers inside two different people.
But the surgery is riskier than kidney donation. Just a few hundred live liver donations occur each year, and only 22 liver transplants have been performed as part of a pair, a UNOS spokesman said.
As Deveza became more sick at home in Gilroy, California, John Dickerson was on the other side of the country, at Carnegie Mellon University in Pittsburgh, working on his doctoral dissertation in computer science.
In his work on "multi-organ exchange," Dickerson examined paired and chained donation and looked at mathematical formulas for increasing the number of organs available for transplant. Some of Dickerson's earlier work had led to refinements in UNOS's system for matching donors and recipients, he said. He posted drafts of the research, conducted with his adviser, Tuomas Sandholm, online as he developed his ideas.
"What my paper shows is that . . . in theory you increase the number of transplants by a substantial amount," said Dickerson, now an assistant professor at the University of Maryland.
"It should increase 25 to 30 per cent."
In 2015, Aliana Deveza was a 19-year-old community college student with a mother whose kidney disease was growing worse. She was scouring the web, looking for anything to help, when she stumbled across Dickerson's research.
"I was actually just looking at other types of transplant procedures that are done," she recalled. "If I can't donate my kidney, what other thing could I donate so my mum could get a kidney?"
She read Dickerson's paper, full of equations and charts and Greek letters, and didn't understand that it was presenting a theoretical model. The next morning she was on the phone to transplant hospitals in California, trying for a spot in the programme he described.
"Nobody knew what I was talking about," she said. "They didn't know which department to transfer me to. One hospital I talked to wanted to transfer me to the morgue."
No one had proposed swapping a liver for a kidney in a paired donation before.
She emailed Roberts, who runs the liver transplant programme at the University of California at San Francisco. "Like the paired kidney exchange, would it be possible to donate (i.e. a part of my liver) to a recipient in need of it and in exchange my mum would be the recipient of the other donor's kidney?" she wrote.
Roberts found the email the next morning. "When I read that, I was excited," he said. "Because it was brilliant."
The Devezas were brought in. Tests were done. And then they settled down to wait.
Eighteen months later, UCSF found a match. Two sisters, one in dire need of a liver, the other willing to donate a kidney.
"I wanted to be a donor for my sister," said Annie Simmons, 49, a fitness trainer and pet-sitter in Caldwell, Idaho. But her liver was too small for Connie Saragoza de Salinas, who lives in Sacramento.
Two weeks later, the coordinators called back and proposed the swap. "I didn't even know what they were talking about," she said.
"I was really scared. I had a lot of questions. What if I don't make it? Will I be able to exercise again. Will I be normal?" Within a day, thought, she agreed to participate.
"It's changed me inside," Simmons said. "It's changed my heart. I know it's something God put there. It was something I needed to do to save her."
When the testing showed the surgery could go forward, there was one last hurdle to clear. Because the risk to Aliana Deveza was much greater than the risk to Annie Simmons, the doctors had to decide whether this first-ever arrangement was ethical.
According to a journal article that examinedthe ethics of this exchange, a liver donor faces a 1 in 500 chance of death, while a kidney donor faces a 1 in 3000 chance of dying. UCSF's ethics committee deliberated and approved the transplants.
On July 20, 2017 at UCSF, surgeon Nancy Ascher removed the right lobe of Aliana Deveza's liver, which Roberts (who is Ascher's husband) then implanted in Connie Saragoza. Other surgeons removed Erosalyn Deveza's two badly impaired kidneys and Annie Simmons's healthy left kidney, which was implanted in Erosalyn Deveza.
Saragoza suffered life-threatening complications after surgery, according to Simmons and Roberts, but is doing well now. (Saragoza did not return requests for comment.) Though she is on immunosuppressant medication and other drugs, Deveza is much improved and has resumed working full time.
In the past two years, UCSF has tried to arrange other liver-kidney swaps, but without success so far. UNOS said it is not aware of another one, before or since.