Observations on Renal Hypertension. the Role of Renal Biopsy.

INTEREST in unilateral renal disease as a possible cause of human hypertension originated with Goldblatt 's classic experiments.' In 1937, Butlerreported the clinieal cure of hypertension following nephrectomy in two cases of unilateral, pyelonephritis with vascular disease in children. In recent years it has been recognized that many cases of human hypertension are on the basis of unilateral renal disease,3-7 and unilateral nephreetomy has been performed in many such eases. When ischemia has been found due to stenosis or partial obstruction of a main renal artery, repair of the vascular lesion in various ways (without nephrectomy) has been practiced, with favorable results reported in some cases.3-'3 The number of hypertensive patients treated by unilateral nephrectomy or repair of the main renal artery has been mounting precipitously. In a review article5 it has been stated that "there are upwards of two million subjects with undiagnosed renal artery stenosis in the United States of America." The implication of this, and of similar statements, is that all of these persons are potential candidates for surgery. Great interest in the development of technics to detect unilateral renal disease followed the reports of Smith'4' 15 and of Thompson.16 Smith15 found that 26 per cent of 535 patients had been cured of hypertension as a result of unilateral nephrectomy, but cautioned that many unsuccessful cases probably had not been reported. However, he eliminated nmany