Duplex Doppler sonography for renal artery stenosis in the post-transplant pediatric patient

Of 60 renal transplant patients who underwent 134 duplex Doppler sonograms, 38 had normal frequency shift profiles and 8 showed only minimal disturbances, within normal post-transplantation limits. Fourteen patients had hypertension and showed a very abnormal profile. In 3 of the 14 the hypertension was controllable medically, and the remaining 11 underwent angiography. Duplex Doppler sonography showed gross turbulence (spectral broadening, bidirectional flow) and high frequency shift confirmed on angiography to represent 50 to 75% main renal artery stenosis in 8 of these 11, and major renal intrahilar vessel stenosis in 2. In the remaining patient, no Doppler signal was found and 95% stenosis was present. In 1 patient with intrahilar stenosis, arterial signals detected in the renal veins indicated the presence of a post-biopsy arteriovenous fistula. One patient with main renal artery stenosis also had a fistula, which was masked by a 70% stenosis. All patients with angiographically proven renal artery stenosis had a distinctive abnormality of the Doppler arterial flow pattern.