Duplex Ultrasound Findings Before and After Surgery in Children and Adolescents with Renovascular Hypertension

We report our experience with duplex ultrasound in young patients with renal artery stenosis (RAS) or middle aortic syndrome (MAS) before and after surgery (1995 and 2009). Of 36 patients (mean age: 13 ± 7 y), 21 had RAS and 15 had MAS. For patients with RAS, the Vmax in the affected artery was 350 ± 111 cm/s before surgery and 145 ± 55 cm/s after surgery. The resistance index was 0.46 ± 0.1 in the post-stenotic kidney and increased to 0.60 ± 0.08 after revascularization. Determination of the flow profile in the iliac artery revealed triphasic flow. In individuals with MAS, Vmax in the aorta was 323 ± 98 and the resistance index in both kidneys was low, even in the absence of RAS. The flow profile in the iliac arteries was monophasic before surgery and became triphasic after surgery. Duplex ultrasound is useful for the evaluation of children and young adults both pre- and post-surgery. Duplex ultrasound criteria for RAS in adults appear to be applicable in children and young adults also. The diagnostic evaluation of suspected renal vascular disease should include assessment of the aorta and the flow profile in the iliac arteries, as this could help differentiate between aortic and isolated renal artery stenosis.