CLINICAL-EVIDENCE OF CONTRALATERAL RENAL PARENCHYMAL INJURY IN PATIENTS WITH UNILATERAL ATHEROSCLEROTIC RENAL-ARTERY STENOSIS

It has been postulated that the kidney contralateral to a significant renal artery stenosis may be at risk for accelerated arteriolar nephro sclerosis. Duplex ultrasound is capable of detecting and classifying r enal artery stenosis and examining parenchymal flow. Renal flow patter ns are a reflection of resistance, which increases with parenchymal pa thology. One-hundred fifty-one patients with atherosclerotic renal art ery stenosis (ARAS) were prospectively studied with duplex ultrasonogr aphy. Renal arteries were classified as normal, <60% stenosis, greater than or equal to 60% stenosis, or occluded. The renal artery end-dias tolic ratio (EDR) (end-diastolic velocity/peak systolic velocity) was measured. EDR decreases as resistance to flow increases. There were 81 patients with a unilateral greater than or equal to 60% ARAS. The EDR was significantly lower in the kidney contralateral to the greater th an or equal to 60% ARAS (0.27 +/- 0.08 versus 0.30 +/- 0.08; p = 0.001 , paired t-test). The absolute difference in EDR was even more pronoun ced in the subgroup of 15 diabetic patients with a greater than or equ al to 60% ARAS (0.22 +/- 0.08 versus 0.27 +/- 0.08; p = 0.004). This s tudy offers clinical evidence that a unilateral hemodynamically signif icant ARAS is associated with the development of arteriolar nephroscle rosis in the contralateral kidney. These results have important implic ations on blood pressure control, renal function, and response to rena l revascularization in this patient population.