DIAGNOSIS OF RENAL-ARTERY STENOSIS IN TRANSPLANTED KIDNEYS - VALUE OFDOPPLER WAVE-FORM ANALYSIS OF THE INTRARENAL ARTERIES

OBJECTIVE. The objective of this study was to determine in renal trans plant patients if the acceleration time and subjective assessment of d ampening of the waveforms from the intrarenal arteries improves the ac curacy of detecting a hemodynamically significant (greater than or equ al to 50%) proximal arterial stenosis compared with measurements of pe ak systolic velocity from a main renal artery. MATERIALS AND METHODS. In 15 patients, the findings of 19 Doppler sonograms and corresponding arteriograms of their renal transplants were reviewed, with arteriogr aphy serving as the gold standard, Four patients had a significant pro ximal arterial stenosis; three were of the main renal artery and one w as of the adjacent external iliac artery proximal to the anastomosis w ith the renal artery. RESULTS. We found a significant prolongation of the acceleration time in patients with a significant proximal arterial stenosis (p = .0004). Use of a threshold acceleration time of 0.10 se c or subjective assessment of dampening of the waveforms resulted in a n accuracy of 95% in detecting a significant proximal arterial stenosi s. This compared with an accuracy of 62% in detecting a significant pr oximal arterial stenosis using a peak systolic velocity threshold of 2 .0 m/sec as the sole criterion. Using intrarenal arterial Doppler wave form parameters alone would have spared arteriography in 11 patients a nd would have detected three of four significant proximal arterial ste noses. CONCLUSION. In this study, Doppler waveform analysis of the int rarenal arteries improved the accuracy of screening for a significant proximal arterial stenosis. The results suggest that such analyses can be used to spare many patients with suspected renal vascular hyperten sion from unnecessary arteriography.