COMPUTED TOMOGRAPHY-DERIVED INTRARENAL BLOOD-FLOW IN RENOVASCULAR ANDESSENTIAL-HYPERTENSION

The effect of renal artery stenosis on intrarenal perfusion and volume in renovascular hypertensive patients is unclear. Alterations in thes e attributes may ultimately be involved in deterioration of renal func tion. We measured whole kidney, cortical, and medullary perfusion and volume with electron beam computed tomography (EBCT) in 33 hypertensiv e patients, with well-preserved renal function, scheduled for renal an giography. EBCT-derived whole kidney perfusion was lower in patients w ith atherosclerotic renal artery stenosis (RAS; N = 20) than in fibrom uscular dysplasia (FMD; N = 10) or essential hypertension (N = 28; P < 0.05), as was cortical perfusion (2.44 +/- 0.16 vs. 3.26 +/- 0.17 and 3.07 +/- 0.09 ml/min/cc tissue, respectively, P < 0.05), but medullar y perfusion was similar. Whole kidney, cortical, and medullary perfusi on correlated inversely with degree of stenosis in FMD, but not in ath erosclerotic RAS. Renal volumes were similar. These results demonstrat e that, in contrast to patients with FMD, in patients with atheroscler otic RAS the decrease in cortical perfusion is not directly related to the degree of stenosis in the main renal artery. Factors other than t he stenosis itself may play a role in the pathophysiology of atheroscl erotic RAS and associated renal failure.