The reflush effect--a prospective analysis of late perfusion.

This prospective randomized trial examines the effect of a "reflush" with preservation solution immediately prior to renal allograft implantation, using hyperosmolar citrate (HOC, n = 10) or phosphate-buffered sucrose (PBS140, n = 10) versus no reflush (n = 10). All kidneys had been stored in HOC. The HOC reflush did not alter the postpreservation intra- or extracellular electrolyte milieu, whereas the PBS140 reflush resulted in an apparent overall loss of both sodium and potassium from the kidney (P < 0.0005). A small amount of calcium was released into the venous effluent in both reflush groups. A similar amount of lactic acid was released into the venous effluent of the two reflush groups, reflected by a lower pH (P < 0.0005), and there was a similar loss of lactate dehydrogenase and creatine phosphokinase. An analysis of procoagulant activity in the first urine produced was performed as a marker of reperfusion injury. The median value was higher in the No Reflush group at 457.5 units, compared with 263.0 and 209.0 units for the PBS140 and HOC Reflush groups, respectively (P = 0.06). Reflushing the kidneys reduced the postoperative dialysis requirement (from 40% to 15%), but by the end of the first posttransplant week there was no significant difference between the renal functional analyses of the three groups, and there was no difference at one year. The proposed mechanism for the early renal functional improvement is a reduction in the calcium paradox and free radical formation, by release of calcium and ATP breakdown products into the venous effluent prior to implantation.