Evaluation of Native Kidney Recovery After Simultaneous Liver-Kidney Transplantation

Background. Debate continues about which liver transplantation candidates with impaired renal function should undergo liver transplant alone versus simultaneous liver-kidney transplantation (SLK). Identifying predictors of native kidney function recovery after SLK requires an accurate measure of the relative function of all three kidneys in patients with SLK. Methods. The distance of a transplanted kidney from the renal scan camera can be substantially different from that of native kidneys. We developed a technique to correct attenuation of counts of all three kidneys based on their depth. Results. In our series of 13 SLK recipients, attenuation correction increased the measured renal function of native kidneys by up to 40%, demonstrating the importance of this procedure for accurately measuring kidney function. Eight patients met the United Network for Organ Sharing (UNOS)-proposed criteria for receiving a SLK, but four of these still had significant native kidney function (>40% of total function) after transplant. Five patients did not meet the UNOS-proposed criteria for SLK, yet only one of these had native kidney function recovery. Conclusion. The criteria proposed by UNOS to determine that SLK is indicated, and thus that native kidney recovery is not expected, are not always accurate. Further study of factors associated with native kidney recovery after SLK is required.