The predictive value of arterial renal blood flow parameters in renal graft survival

Renal allograft survival depends on a number of factors, however, no reliable simple parameter has been shown to predict long-term outcome after transplantation. Ultrasound is recognized and relatively inexpensive, providing information about renal location, contour, and size. Doppler ultrasonography shows kidney morphology and hemodynamics. The aim of this study was the evaluation of whether Doppler ultrasound of renal arteries performed in the early stage after transplantation was a valuable predictor for long-term-outcomes.

The study included 17 female and 24 male patients, aged 17-69 years with stable graft function. The Doppler ultrasound of renal flow was done on the 1st and 3rd day after transplantaion, and estimated glomerular filtration rate (eGFR) on the 20th day. The measured indices were as follows: maximum blood flow velocity (V(max)), minimum blood flow velocity (V(min)), resistive index (RI), and pulsatile index (PI). The creatinine concentration was evaluated, and eGFR calculated.

Mean renal and intrarenal artery RI increased to day 3 after transplantation, and then reduced. The mean renal and intrarenal V(max) at day 3 correlated positively with eGFR (r = 0.38; P = .015); (r = 0.45; P = .003, respectively). Mean renal and intrarenal V(min) correlated positively with eGFR (r = 0.50; P = .001; r = 0.41; P = .008, respectively). The mean renal and intrarenal V(max) and V(min) on day 1 did not correlate with eGFR.

Early Doppler Ultrasonography of renal graft hemodynamics may be a valuable predictor of graft survival and long-term outcomes. Blood flow velocity within renal arteries seemed to be an important factor.