Liver transplantation is currently the only cure for pediatric acute liver failure (PALF), a rapidly progressing and life-threatening condition that can affect previously healthy children. Some children do not get a transplant in time because of a lack of suitable organs. The Organ Procurement and Transplantation Network (OPTN) has periodically revamped its organ allocation policies over the years to prioritize sicker children over adults and expand the geographic area of donors. A recent study led by Children's Hospital Los Angeles showed that this has helped improve the odds for children with PALF.
The researchers conducted a retrospective cohort study of 1,495 patients with PALF to investigate how changes in patient prioritization and organ allocation impacted waitlist mortality and survival after liver transplant and published the results in JAMA Surgery. "We realized that nobody had actually studied this," says Juliet Emamaullee, MD, PhD, FRCSC, FACS, Research Director, Division of Abdominal Organ Transplantation. Her team grouped the successive changes in allocation over twenty years into three different eras and compared them to patient outcomes.
"We observed that the intentional policy changes relating to acute liver failure in children and prioritization of children on the waiting list resulted in clinically meaningful and statistically significant improved outcomes for these patients," says Dr. Emamaullee.
Reduction in demographic risk factors
Analysis of multiple competing variables revealed that if children were younger than 2 years old—an age where it is harder to find a size-matched liver; or of Hispanic ethnicity; or received a split liver graft from a deceased donor instead of a whole liver, they experienced a higher risk of death after liver transplant in Era 1. But these variables did not seem to affect outcomes by Era 3. Likewise, children under two years of age had a higher risk of graft failure in Eras 1 and 2, but this extra risk disappeared by Era 3 after the policy changes were implemented.
"Most of the kids that we transplant are under five and so finding size-matched organs is really difficult," says Dr. Emamaullee. "The reason our center has been so successful is that we have been expansive in our willingness to split adult livers into a segmental graft—called a technical variant graft—to get those small kids transplanted with adult organs." But even that is challenging, she notes, because adult livers vary so much in size. The changes in allocation policies meant that over the time periods studied, transplant centers were more likely to get younger, smaller donors from a wider geographic area which resulted in higher quality organs for children that were better matched to their body size. Meanwhile, the outcomes for split-liver grafts improved as well over time. CHLA is one of the few transplant centers in the US where this procedure is performed, as it requires specialized training. "Our study showed that these policy changes were associated with substantially decreased deaths on the pediatric waitlist, increased rates of liver transplant and improved post-transplant outcomes," says Dr. Emamaullee.
