Transplant renal artery stenosis: evaluation with duplex sonography.

Determination of the cause of hypertension in renal transplant recipients has required invasive studies such as angiography. Consequently there has been recent interest in noninvasive evaluation. Over a 19-month period, duplex sonography was performed on the renal transplant vasculature in 31 allograft recipients who also underwent correlative arteriography. One patient underwent a repeat duplex study and arteriography after surgical repair. On the basis that a frequency shift greater than 7.5 kHz and associated distal turbulence indicate stenosis, 18 duplex sonographic studies were considered positive. Subsequent angiography showed renal artery stenosis in 16 patients and no significant lesion in two. In 14 patients Doppler studies were interpreted as normal; angiography showed no significant arterial abnormality in 13 and significant stenosis in one. These results indicate a sensitivity of 94.1% and specificity of 86.7% for duplex sonography in the diagnosis of transplant renal artery stenosis. Duplex sonography appears to be an excellent noninvasive screening method to evaluate arterial stenosis following renal transplantation.