PS-R07-4: EFFICACY OF DOPPLER ULTRASOUND FOR INVESTIGATING THE CAUSE OF WORSENING RENAL FUNCTION AND HYPERTENSION IN A CASE OF RENOVASCULAR HYPERTENSION

Abstract

A 72-year-old man visited our hospital after his blood pressure increased from 130/80 to 170/95 mmHg and systemic edema appeared over the past two months. His renal function also deteriorated, with serum creatinine increasing from 2.0 to 4.7 mg/dL. He had developed hypertension aged 40 years and cerebral infarction aged 66 years, and had smoked from 16 to 55 years old. Upon admission, plasma renin activity was 14.8 ng/mL/h, serum aldosterone was 169.4 pg/mL, and he was under treatment with telmisartan 40 mg/day, bisoprolol 5 mg/day, cilnidipine 20 mg/day, and nifedipine 20 mg/day. Computed tomography showed a calcified lesion at the root of the right renal artery and atrophy of the left kidney. There was no postrenal renal failure. On Doppler ultrasound, the right intrarenal artery had no systolic peak wave and the blood flow waveform rose slowly, suggesting renal artery stenosis. Therefore, we suspected that the cause of worsening renal function and hypertension was the deterioration of his one remaining functional (right) kidney, treatment with angiotensin II receptor blocker, and progression of right renal artery stenosis. As this case met the indication criteria for percutaneous transluminal renal angioplasty (PTRA) (resistant to treatment, exacerbated hypertension, and renal artery stenosis in one kidney), we performed angiography and PTRA despite end-stage renal failure. Angiography revealed > 90% stenosis at the root of the right renal artery, and the patient was diagnosed with renovascular hypertension. Following renal artery stenting, the renal stenosis disappeared, blood pressure decreased to 135/75 mmHg, renal function improved to serum creatinine level 2.2 mg/dL, and the edema disappeared. On renal Doppler ultrasound, the waveform of intrarenal blood flow in the right kidney showed a normal pattern. In this case of renovascular hypertension, renal Doppler ultrasound was useful for investigating the cause of worsening renal function and hypertension that occurred over a period of several months.