RÉSUMÉ
Hypertension may be due to either vascular (renal artery stenosis) or nonvascular (urologic) causes in hypertensives with unilateral small kidneys. Generally, the occurrence of hypertension in association with difference in kidney size suggests the presence of prolonged renal artery stenosis. This condition can result in decreased volume of the poststenotic kidney. Another cause of small kidneys is unilateral renal agenesis, renal dysplasia with or without reflux, tubular obstruction, and hydronephrosis. Hypertension can be attributed to abnormal-sized kidneys. Nephrectomy of the small kidney or correction of the stenotic artery normalizes blood pressure. De Jong and associates reported 8 cases of young women thought to have hypertension caused by unilateral renal parenchymal disease. Renal angiography, however, disclosed significant renal artery stenosis in the contralateral kidney of all 8 patients. Revascularization of the kidney with stenotic lesions cured the hypertension. The data suggests that in patients suspected of having hypertension caused by unilateral renal parenchymal disease, not only should renal venous renins be determined, but nephrectomy should not be peformed as well until renal angiography has been performed to exclude contralateral renal artery stenosis. We report a case of unilateral renal artery stenosis with contralateral hypoplastic kidney in a 22 year old woman; hypertension was corrected by successful anastomosis of the stenotic artery without nephrectomy of the contralateral small kidney.