Background: Resistive index (RI) measured by Doppler sonography during the early post-transplant period reflects interstitial oedema within the transplanted kidney. In the present, prospective study we have analysed the influence of RI measured shortly after KTx on graft survival and kidney function during the 5 years follow-up period.
Material/Methods: RI was measured at 2[sup]nd[/sup]-4[sup]th[/sup] day after KTx in 323 out of 333 consecutive patients transplanted in our Centre. Nineteen patients with primary non-functioning graft were excluded from the study. Remaining 304 patients were divided into two groups: first, consisted of 113 patients with RI values below 0.75, and the second one (N=191) with RI equal or above 0.75. The kidney graft function was analyzed using the MDRD formula after 3 months and every 6 months after KTx.
Results: During the 5 years follow-up period 21 patients died (4 in group I and 17 in group II) and 46 lost their kidney graft, 11 in group I and 35 in group II. There was an 8.6% difference in 5-years graft survival with the worse outcome in group II [HR of graft loss 1.98(1.02-3.35); p=0.044]. Patients in group II were characterized by lower eGFR calculated at 3 months post KTx [48.7(46.0-51.5) vs. 60.9(56.8-65.0) ml/min/1.73 m2; p<0.001].
Conclusions: High intrarenal vascular resistance demonstrated by Doppler
sonography shortly after KTx increases the risk of chronic graft dysfunction and almost doubles the likelihood of graft loss during the 5 years follow-up period.

Keywords: Kidney Transplantation, Organ Perfusion