Comparative efficacy of renal preservation solutions to limit functional impairment after warm ischemic injury

In kidney transplantation, cold storage is the dominant modality used to prolong organ viability ex vivo, but is inevitably followed by a period of warm ischemia. Preservation fluids limit tissue damage during the ischemic period, but there is little information on the influence of preservation fluids on the physiologic consequences of warm ischemia alone, or on the comparative ability of such preservation fluids to limit warm ischemic injury. In this study, warm ischemia was induced in rat kidneys by crossclamping the left renal pedicle for 45 min with contralateral nephrectomy. The ischemic kidneys were flushed with Euro-Collins (EC), hyper osmolar citrate (HOC), University of Wisconsin (UW), or phosphate buffered sucrose (PBS) 140 solution. Over a period of 2 h after reperfusion, urine and blood samples were collected and physiological parameters related to the function of the postischemic kidneys were assessed. The data show that postischemic renal function can be influenced by the choice of preservation fluid. Essentially, the continued use of EC as a renal preservation solution finds little support in these data, and, while HOC and UW solutions were better able to limit the decline in renal function after warm ischemia than EC, the solution most able to limit functional impairment after warm ischemia was PBS140. This analysis compares the efficacies of the commonly used preservation solutions and could form the basis for future solid-organ transplant studies that may ultimately allow us to propose best-practice guidelines and an optimum platform for improved preservation solutions.