Trends over a decade of pediatric liver transplantation in the U.S.

A new study on children undergoing liver transplants found that although innovative transplant techniques have been developed in recent years, the waitlist times for pediatric transplant candidates have increased compared to the early 1990s.

In addition, although waitlist deaths have decreased for children overall, they have remained essentially the same for infants.

The results of this study appear in the April 2006 issue of Liver Transplantation, the official journal of the American Association for the Study of Liver Diseases (AASLD) and the International Liver Transplantation Society (ILTS). The journal is published on behalf of the societies by John Wiley & Sons, Inc. and is available online via Wiley InterScience.

Beginning with the first successful liver transplant in 1967, pediatric transplantation has played a major role in developing new techniques for successful liver transplants. Following the introduction of the immunosuppressant cyclosporine in 1980, multiple transplant centers were established worldwide in the 1980s and long-term survival has continued to increase since then. However, due to the nature of childhood liver disease, infants and toddlers are more commonly transplant candidates than older children, and a shortage of appropriate sized livers has translated into a mortality rate as high as 40 percent for young patients awaiting transplant. Splitting one liver into two smaller grafts, utilizing techniques for reducing an adult-sized liver, developing living donor transplants, and employing novel microsurgery techniques are the latest options available to pediatric patients. The current study compared the profile of these patients in the early 1990s to more recent liver transplant patients.

Led by Sandy Feng, M.D., Ph.D., of the Department of Surgery at the University of California San Francisco, researchers compared 1,472 pediatric patients who underwent liver transplants between January 1990 and December 1992 to 1,420 patients who had transplants between March 2002 and December 2004. They found that more children between 11 and 17 years old and fewer children 1 to 5 years old received transplants in the later period. In addition, while biliary atresia (a congenital absence of the bile ducts) remained the most common indication for a transplant, it accounted for almost half of the transplants in the earlier period compared to about one third in the later period, while there was an increase in tumors as an indication for transplant. The number of pediatric patients on the waitlist increased only slightly in more recent years, but the average waiting time for a transplant increased significantly. These changes in waitlist characteristics and times for pediatric candidates were juxtaposed against those for adult candidates which have also increased even more dramatically.

"As expected, based upon our premises in selecting two eras of pediatric liver transplantation for comparison, there was a major shift towards the use of technically demanding grafts particularly to achieve transplantation of the youngest candidates, the infants and toddlers," the authors note. They add that while children now account for only 6 percent of the waiting list compared to 15 percent a decade earlier, waiting times have increased and it is the youngest patients who continue to suffer more disease and death due to insufficient organ supply. The authors conclude: "We hope that our observations motivate studies and initiatives which aim to improve access and outcomes for young children, particularly infants, in need of liver transplantation."

In an accompanying editorial in the same issue, Benjamin Shneider and Sukru Emre of the Mount Sinai Medical Center in New York note that infants with liver disease represent a distinct challenge, from both a surgical and medical perspective. Newborns tend to have either neonatal liver failure or true acute liver failure that develops immediately after birth. "Supportive care for these children is technically very difficult due to their small size and it is not surprising that these children have a high waitlist mortality," they state. In recent years, improved post-transplant survival has resulted in expanding indications for liver transplants in children. However, the authors advise caution regarding this practice, noting that pediatric transplants are often tied into adult programs, despite the fact the overall numbers of transplants in children have remained unchanged. "Typically, it is not economical to maintain programs that have low annual volume and as such there will be pressure to increase volume at all of these programs," the authors note, adding that this presents a potential conflict of interest to those providing care. Finally, one of the biggest challenges in pediatric liver transplants lies in the fact that the number of adult transplants has increased significantly in recent years, and children and adults potentially compete for the same organs. Noting that this problem may become critical, the authors conclude: "Split rather than reduced-size liver transplantation should be strongly encouraged as it allows children and adults to share rather than compete for livers from adult donors."