Comparison of preservation solutions in an experimental model of organ cooling in kidney transplantation.
Viscous preservation solutions such as University of Wisconsin solution (UW) may be less effective at rapid removal of blood from an organ so that cooling takes longer. This study assessed the temperature changes of kidneys flushed with UW and hyperosmolar citrate (HOC). Porcine kidneys were retrieved and flushed with 500 ml UW or HOC at 4 degrees C while monitoring kidney temperature at depths of 5 and 20 mm. Renal function was measured on an isolated organ preservation system. The mean(s.d.) rate of temperature fall was slower with UW (at 20 mm: 0.64(0.11) versus 1.01(0.56) degrees C per min per 100 g; P = 0.016). The perfusion flow rate required to reduce the temperature to less than 10 degrees C at a depth of 20 mm was lower in the UW group (P = 0.002). Kidneys flushed with HOC gained more weight than those flushed with UW (mean(s.d.) 50(8) versus 7(13) per cent; P = 0.002). Flushing with UW was associated with less histological injury but there were no significant differences in renal function parameters between the groups. UW cooled kidneys more slowly than HOC, but with no adverse effect on renal function. UW resulted in less oedema and histological injury than HOC.