Parenchymal consequences of fibromuscular dysplasia renal artery stenosis

The aim of this study is to assess parenchymal consequences of fibromuscular dysplasia (FMD) renal artery stenosis (RAS) in hypertensive patients by spiral computed tomographic angiography (CTA).

Spiral CTA was performed in 20 essential hypertensive (EH) patients (40 EH kidneys and 20 hypertensive patients with unilateral FMD stenosis (20 poststenotic [S] kidneys, 20 opposite [OPP] kidneys). Renal length (RL; in millimeters), mean cortical thickness (MCT; in millimeters), cortical area (CA; in square millimeters), and medullary length (ML; in millimeters) were evaluated.

Blood pressure, creatinine clearance, and long-standing hypertension were similar in both groups of patients. Compared with EH kidneys, S and OPP kidneys showed significant cortical thinning (MCT(EH) = 9.2 +/- 0.8 mm versus MCT(OPP) = 7.8 +/- 1.0 mm versus MCT(S) = 7.3 +/- 1.0 mm; P < 0.0001). RL and ML were reduced only in the S kidney group, with RL(EH) = 103 +/- 11 mm versus RL(OPP) = 105 +/-10 mm versus RL(S) = 96 +/- 11 mm; P = 0.05; and ML(EH) = 84 +/- 11 mm versus ML(OPP) = 89 +/- 9 mm versus ML(S) = 81 +/- 10 mm; P = 0.05, respectively. CA and MCT correlated significantly with creatinine clearance in the entire population (r = 0.43; P = 0.005; r = 0.35; P = 0.02, respectively).

Unilateral RAS was associated with bilateral cortical thinning in FMD disease. Cortical atrophy appears to be an accurate marker of unilateral RAS. Its use as a potential screening method for RAS should be investigated further.