[Role of echo-Doppler in the screening of renal artery stenosis in children with kidney transplants].

Renal artery stenosis (RAS) in renal transplanted pediatric patients is a long-term complication. The clinical suspicion must be considered when patients exhibit signs of impaired renal function or refractory hypertension, not associated with other complications of renal transplantation -i.e., acute or chronic rejection, glomerulonephritis, cyclosporine toxicity. The intermediate step between clinical suspicion and angiography is represented by Doppler US. The authors report their experience with Doppler US in the screening of RAS in a pediatric series of transplanted patients. The incidence of RAS in our series (54 transplanted kidneys, 46 of them included in the study) was 4.3%. A severe stenosis was demonstrated by both Doppler US and angiography in 2 patients, with 100% Doppler sensitivity. In both stenoses, Doppler US showed high systolic peaks (blood flow velocity > or = 2.5 m/s) and post-stenotic turbulence. Thanks to its high sensitivity, Doppler US is considered to be very useful in the screening of vascular complications in renal transplanted children.