[Renovascular hypertension due to unilateral renal artery stenosis with hypokalemic alkalosis, the salt-losing syndrome and reversible hyperechogenicity of the contralateral kidney. A study of 2 infants].

This report describes two infants with severe arterial hypertension secondary to unilateral renal artery stenosis which was manifested by polyuria, polydipsia, hypokalemic alkalosis, hyponatremia, increased natriuresis and increased plasma values of rennin and aldosterone. On sonographic examination, the contralateral non-stenotic kidney of both patients appeared enlarged and hyperechogenic mimicking parenchymal lesion. When the patients became normotensive, their sodium and potassium balance became normal and their contralateral non-stenotic kidney also became normal in size and echogenicity. The increase of the filtration and the natriuresis observed in the contralateral non-stenotic kidney of the patients with renovascular hypertension due to renal artery stenosis might be responsible for the hyperechogenicity. When the patients became normotensive, the filtration and excretion of sodium of the contralateral kidney also became normal and the increase of echogenicity also disappeared. The reversibility of the sonographic findings suggest a functional origin.