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[Intrarenal color Doppler ultrasound for exclusion of renal artery stenosis in cases of multiple renal arteries. Analysis of the Doppler spectrum and tardus parvus phenomenon].

PURPOSE
To diagnose possible renal artery stenosis especially in case of multiple renal arteries by intrarenal colour-coded Duplex sonography.


METHODS
In 50 hypertensive patients lobar and interlobar arteries were looked for at 3 different levels. Analysis included the determination of the early systolic acceleration time and the assessment of the Doppler waveform, especially the "tardus-parvus" phenomenon. Intraarterial angiography was performed in all patients the next day.


RESULTS
In 48/50 patients the sonographic investigations were sufficiently evaluable. Angiography showed haemodynamically relevant stenosis in 13 patients, in 4 patients bilaterally. In 21 patients (42%) multiple renal arteries were found. Sensitivity and specificity in the diagnosis of renal artery stenosis was 77% respectively 46% (threshold value > or = 0.120 s). In 10/17 angiographically verified haemodynamically relevant renal artery stenosis a change of the Doppler waveform was noted; sensitivity in the diagnosis of renal artery stenosis was 69%, specificity 90%.


CONCLUSION
Intrarenal colour-coded Duplex sonography cannot be recommended as a screening tool for renal artery stenosis.