Resistive Index of the Remaining Kidney in Allograft Kidney Donors

Abstract

Kidney transplant is the last resort in patients with end-stage renal disease. In living-kidney donors undergoing nephrectomy for transplant; however, morphologic and hemodynamic changes may occur in the remaining kidney with time. If there would be such a change, then it may alter the diagnostic utility of Doppler ultrasound in evaluating diseased conditions of the solitary kidney. Using Doppler ultrasound, this study sought to determine whether there are hemodynamic changes in the remaining kidney. Forty-one patients (38 men, 3 women) for kidney donation were examined using a MyLab 50 color Doppler apparatus with a convex 3.5- to 5-MHz probe. Resistive index values of the main renal, interlobar, and interlobular arteries in the remaining kidney were assessed before, and at 7 and 90 days after nephrectomy. The size and parenchymal thickness of the remaining kidney also were measured before and after nephrectomy. At day 90, a statistically significant increase (P < .001) in resistive index was seen at all levels, compared with before and 7 days after nephrectomy. No significant changes, however, could be noticed on the day 7, when compared with before the nephrectomy. Renal size and parenchymal thickness remained constant over the time studied. Although a statistically significant increase in resistive index values of the remaining kidney was seen 90 days after the nephrectomy, these values have remained within the normal limits of renal resistive index. So, our findings indicate that resistive index measurement is useful in assessing the diseased condition of the remaining kidney after removing the contralateral kidney.