[Two cases of renovascular hypertension detected by 2-D Doppler method]

Renovascular hypertension is most frequent causes of secondary hypertension. Although angiography of renal artery is reliable procedure for the diagnosis of the renovascular hypertension, it is expensive and invasive. We report two cases which become possible to make diagnosis of the renovascular hypertension by measurement of velocity of segmental or interlobar artery using 2-D color Doppler method. Case 1: 39 year-old male was hospitalized because of hypertension (200/130 mmHg). Ccr was 82 ml/min. 2-D Doppler test demonstrated that the Vmax, the Vmin and the Vmin/Vmax of the right segmental artery were 40 cm/sec., 24 cm/sec. and 0.60, respectively. The Vmax, the Vmin, and the Vmin/Vmax of the left segmental artery were 42 cm/sec., 22 cm/sec. and 0.52, respectively. Renal angiography shows right renovascular stenosis. After percutaneous transluminal angioplasty, the blood pressure became normal and Vmin/Vmax ratio of the right segmental artery was down to 0.52. Case 2: 46 year-old male was hospitalized because of chronic renal failure (Ccr: 14.6 ml/min) and uncontrollable hypertension. 2-D Doppler test demonstrated that the Vmax, the Vmin, the Vmin/Vmax ratio and the acceleration of the right segmental artery were 10 cm/sec., 6 cm/sec., 0.62 and 1.7 m/sec.2, respectively. The Vmax, the Vmin, the Vmin/Vmax ratio and the acceleration of the left interlobar artery were 8 cm/sec., 5 cm/sec., 0.63 and 0.8 m/sec.2, respectively. Renal angiography shows bilateral renovascular stenosis. Thus, the elevated value of Vmin/Vmax ratio (over 0.6) (mean value: 0.43 +/- 0.08, when Ccr is over 70 ml/min, whereas 0.32 +/- 0.11, when Ccr is under 30 ml/min) and decreased acceleration (under 2.0 m/sec. 2) of the segmental or the interlobar artery seems to be helpful for the diagnosis of renovascular hypertension.