Outcomes of dual adult kidney transplants in the United States: An analysis of the OPTN/UNOS database

Background. The organ shortage has resulted in increased use of kidneys from expanded criteria donors (ECD). For ECD kidneys unsuitable for single use, dual kidney transplants (DKT) may be possible. There are limited data comparing outcomes of DKT to single kidney ECD transplants, making it unclear where DKT fits in the current allocation scheme. Our purpose was to compare outcomes of DKT and ECD transplants in the United States. Methods. From 2000 to 2005, a total of 625 DKT, 7686 single kidney ECD, and 6,044 SCD transplants from donors aged >= 50 years were identified from the Organ Procurement and Transplantation Network/United Network for Organ Sharing data. Allograft survival was the primary outcome. Results. DKT comprised 4% of kidney transplants from donors aged >= 50 years. Compared to the ECD donor group, the DKT donor group was older (mean age 64.6 +/- 7.7 years vs. 59.9 +/- 6.2 years) and consisted of more African Americans (13.1% vs. 9.9%), and more diabetic donors (16.3% vs. 10.4%; P < 0.001). Mean cold ischemic time was longer in DKT (22.2 +/- 9.7 hr), but rates of delayed graft function were lower (29.3%) compared to ECD transplants (33.6%, P=0.03). Three-year overall graft survival was 79.8% for DKT and 78.3% for ECD transplants. Conclusion. DKT were infrequent and had outcomes comparable to ECD transplants, despite the use of organs from higher risk donors. With a more upfront approach to DKT by offering this option to patients at the time of wait-listing as part of an ECD algorithm, we may be able to further optimize outcomes of DKT and minimize discard of potential organs.