NIH Launches Study of Living Donor Liver Transplantation

Bethesda, Maryland �� The NIH today announced the Adult to Adult Living Donor Liver Transplant Cohort Study (A2ALL), to take place at 10 U.S. centers over the next 7 years. The national project will investigate the experience of a group of patients eligible for living donor liver transplantation, focusing on the factors influencing outcomes of living donor liver transplants for both donors and recipients. Researchers will compare outcomes of this new procedure with the outcomes for patients who receive livers from cadavers.

"Our goal is to gather accurate data in a disciplined, careful way so we can give liver transplant patients and potential donors solid information about the risks and benefits of this innovative and controversial procedure," says Jean Emond, M.D., chief of transplantation services at Columbia University and a co-chair of the study. Carl L. Berg, M.D., director of hepatology at the University of Virginia, is also a co-chair. In addition to vital clinical issues, the A2ALL will investigate important research issues such as liver regeneration, liver cancer, and infectious hepatitis.

Liver transplantation is the only cure and a life-saving measure for people with end-stage liver disease. Although liver transplants have become relatively common in the United States in recent decades, in 2001 some 17,000 patients waited for livers to be donated, while fewer than 5,000 cadaveric livers were actually donated that year. The shortage of cadaveric organs has led surgeons to look to live donors to close that gap. The liver is a large segmented organ that can potentially be split without harm to the donor and with benefit to the recipient. Because the liver, unlike most organs, has a remarkable ability to regenerate, the donor's remaining liver grows to its original size within weeks. Likewise, the donated lobe will also grow in the recipient's body.

For children in need of liver transplantation, living donor transplantation from an adult has been very successful and has become an accepted medical option. Adults in need of liver transplantation require a larger segment, as much as half or more of the donor's liver. This requires a more extensive and complex surgery, with potentially greater risks for the donor and the recipient. The procedure has evolved so rapidly that over half of the living donor transplants performed to date have occurred since 2000. Evaluation of donors as well as surgical procedures vary from one transplant center to another. Although the large majority of living donor liver transplants have been successful, there are few data to inform potential donors about risks. Post-surgical problems for donors can include infection, pneumonia, and leaking bile, which can require further surgery.

Because the procedure is expanding across the country, a group of concerned doctors called for more research on risks and benefits and an outside regulator to certify hospitals that would perform the procedure in the New England Journal of Medicine (April 4, 2002). They also asked for uniform medical criteria in picking donors and recipients. "There is no regulation of surgical interventions. The A2ALL study can break new ground in shaping the way we approach transplant surgery," adds Robert Merion, M.D., study chair and leader of the data coordinating center at the University of Michigan, Ann Arbor.

"The NIH, with assistance from the American Society of Transplant Surgeons (ASTS) and the Health Resources and Services Administration (HRSA), expects A2ALL to provide much-needed data about what works best in this emerging surgical field," explains James Everhart, M.D., M.P.H., of the National Institute of Diabetes and Digestive and Kidney Diseases, which is funding the study along with the ASTS and HRSA. "Transplant surgeons place a great deal of importance on the well-being of both donors and recipients. This partnership with NIDDK should give us solid data for the high quality patient care we all want to provide," adds James Schulak, M.D., ASTS president. HRSA, like the NIH, is a component of the Department of Health and Human Services.

Editors: A list of Centers, Principal Investigators and Media contacts is attached.