THE TRANSPLANTED NEPHRONIC MASS INFLUENCES RENAL VASCULAR-RESISTANCE AND BLOOD-FLOW OF THE KIDNEY GRAFT

In order to assess whether the transplanted nephronic mass plays a rol e in the progression of chronic graft dysfunction, 83 well-functioning renal transplants were investigated. Plasma creatinine, creatinine cl earance, renal volume, blood flow and renal vascular resistance were m easured. The weight of the donor was considered as an index of the tra nsplanted renal parenchyma and the weight of the recipient as an index of the required nephronic mass. To evaluate the adequacy of the trans planted nephronic mass, the ratio between the donor and the recipient' s weight was calculated. This ratio showed a mean of 1.06 +/- 0.18 and a range between 0.63 and 1.6, indicating that a parenchymal mass betw een 30 and 80% of the physiologic one was transplanted in these subjec ts. Patients were divided into two groups: group A patients with a rat io >1, group B patients with a ratio <1. In group A, a regression anal ysis did not show any relationship between transplant age and creatini ne clearance, renal volume, blood flow and renal vascular resistance a s assessed by echo-color-Doppler ultrasonography. In patients with red uced nephronic mass, group B, there was a negative relationship betwee n renal blood flow and transplant duration (p = 0.03) and a positive r elationship between transplant age and renal vascular resistance (p = 0.01) and renal volume (p = 0.01). These data support the hypothesis t hat the difference in weight between donor and recipient may influence the outcome of the graft.