Delayed graft function of more than six days strongly decreases long-term survival of transplanted kidneys

Abstract

Background: We reviewed 843 first cadaver kidney transplants carried out consecutively at our center to examine the effect on long-term graft survival of the duration of delayed graft function (DGF), defined as the time taken for the kidney to attain the threshold of a Cockcroft calculated creatinine clearance (cCCr) > or = 10 ml/min.

Methods: Using a multivariate Cox survival analysis we evaluated the consequences of DGF on allograft survival, and then by regression analysis identified the factors contributing to the occurrence of DGF. Finally, using a Kaplan Meier analysis we compared the profiles of graft failure according to the duration of DGF.

Results: Defining DGF in terms of cCCr rather than necessity for dialysis after transplantation allowed better prediction of long-term graft loss. Indeed, patients with a Cockcroft-based DGF > six days who did not require dialysis (12%) had a significantly poorer long-term graft outcome than those with a DGF < or = six days. Furthermore, we showed that a DGF of six days could be taken as a cut-off point that marked a significant difference in the long-term graft survival rate (P < 0.0001). Surprisingly, further extension of the duration of DGF > six days was not associated with further worsening of graft survival (except in DGF > 30 days).

Conclusion: Our results suggest a threshold effect in the lesions that ultimately results in long-term functional deficiency. In addition, we show that the need for dialysis is not an adequate criterium for DGF in terms of long-term outcome prediction.