Renal rule 26 : Renal artery stenosis

In patients with uncontrolled hypertension despite multiple blood pressure medications, ultrasound may identify patients with RAS who should go onto renal angiography and angioplasty for cure of their hypertension

With renal artery Doppler, a marked increase in flow at the level of stenosis is detected or downstream from the stenosis, a parvus tardus waveform can be detected

Renal artery Doppler ultrasound (1) screening for renal artery stenosis shows very high velocity flow at the level of the left renal artery origin from the aorta.  This indicated a significant stenosis.  (2) Subsequent arteriogram in same patient shows tight stenosis at the left renal artery ostium.  Following angioplasty, the stenosis was gone and the patient's hypertension resolved.

Screening color Doppler ultrasound with spectral analysis in patient with uncontrolled hypertension despite medical treatment shows classic parvus tardus (slow peak and diminished amplitude to systolic peak) of renal artery waveform distal to a renal artery stenosis. See arrows.