Kidneys From Deceased Donors: Maximizing the Value of a Scarce Resource

Urological Survey RENAL TRANSPLANTATION AND RENOVASCULAR HYPERTENSION Kidneys From Deceased Donors: Maximizing the Value of a Scarce Resource H. U. Meier-Kriesche, J. D. Schold, R. S. Gaston, J. Wadstrom and B. Kaplan, Department of Medicine, University of Florida, Gainesville, Florida, Department of Nephrology, University of Alabama at Birmingham, Birmingham, Alabama, and Department of Surgery, Uppsala University Hospital, Uppsala, Sweden Am J Transplant, 5: 1725–1730, 2005 Donor age is a significant risk factor for graft loss after kidney transplantation. We investigated the question whether significant graft years were being lost through transplantation of younger donor kidneys into older recipients with potentially shorter lifespans than the organs they receive. We examined patient and graft survival for deceased donor kidney transplants performed in the United States between the years 1990 and 2002 by Kaplan-Meier plots. We categorized the distribution of deceased donor kidneys by donor and recipient age. Subsequently, we calculated the actual and projected graft survival of transplanted kidneys from younger donors with the patient survival of transplant recipients of varying ages. Over the study period, 16.4% (9250) transplants from donors aged 15–50 were transplanted to recipients over the age of 60. At the same time, 73.6% of donors above the age of 50 were allocated to recipients under the age of 60. The graft survival of grafts from younger donors significantly exceeded the patient survival of recipients over the age of 60. The overall projected improvement in graft survival, by excluding transplantation of younger kidneys to older recipients, was approximately 3 years per transplant. Avoiding the allocation of young donor kidneys to elderly recipients, could have significantly increased the overall graft life, by a total 27 500 graft years, between 1990 and 2002, with projected cost savings of about 1.5 billion dollars. Editorial Comment: At present the major determinants of deceased donor allocation are wait time and human leukocyte antigen matching. (Children and prior living donors get extra matching points.) There is no stipulation that there be age equity in pairing donor organs and recipients. With the current immunosuppressant medications human leukocyte antigen matching is less important to graft outcome than certain nonimmunological issues, with donor age representing an important variable. This article examines the hypothesis that allocating younger donor kidneys to younger recipients would maximize graft longevity. This effect would occur because older recipients receiving younger kidneys more frequently die with a functioning graft, representing a loss of a scarce resource. In fact, analysis shows that graft survival of younger kidneys is better than patient survival for many older recipients. In essence, the kidney may outlive the patient. From the perspective of the older patient this outcome may be desirable. However, given the scarcity of kidneys as a resource, this outcome represents inefficiency of the allocation system. From 1990 to 2002 more than 9,000 kidneys from donors 15 to 50 years old were transplanted into recipients older than 60 years. If these kidneys were allocated to recipients younger than 60 years (with an improved prospect for patient survival), an additional 27,750 graft years would be gained. This outcome would limit the need for retransplantation for the younger cohort. This result also represents a cost savings of 1.5 billion dollars to the end stage renal disease treatment system. As the organ shortage becomes more acute with the burgeoning end stage renal disease population, maximizing graft lifespan will become more important. This analysis suggests that if age optimization were used there would be a graft survival improvement accrued to the overall system. Nonetheless, segments of the population (older recipients) would have diminished graft survival. David A. Goldfarb, M. D.

0022-5347/06/1752-0648/0 THE JOURNAL OF UROLOGY® Copyright © 2006 by AMERICAN UROLOGICAL ASSOCIATION

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Vol. 175, 648-649, February 2006 Printed in U.S.A. DOI:10.1016/S0022-5347(05)00362-9