Evaluation of renal allograft function by Doppler spectrum analysis. A preliminary study

Area of Science:

• Nephrology
• Vascular Ultrasound
• Transplant Medicine

Background:

• Decreased renal function is common after kidney transplantation.
• Differentiating causes of impaired allograft function is clinically challenging.
• Duplex ultrasonography offers potential for noninvasive assessment.

Purpose of the Study:

• To evaluate quantitative Doppler spectrum analysis for differentiating causes of decreased renal allograft function.
• To correlate Doppler parameters with clinical indicators of renal function.
• To assess the utility of Doppler analysis in distinguishing renal artery stenosis, rejection, and nephrotoxicity.

Main Methods:

• Forty-five renal transplant recipients were studied.
• Doppler spectra were recorded from the renal artery to the allograft.
• Clinical parameters evaluated renal allograft function; Doppler parameters characterized blood flow and peripheral resistance.

Main Results:

• Significant correlations were found between Doppler parameters and clinical indicators of peripheral resistance.
• Normal function showed high diastolic flow (low resistance).
• Renal artery stenosis was associated with low peak velocity and low pulsatility index.
• Rejection or cyclosporin toxicity showed increased peripheral resistance with decreased diastolic velocity.

Conclusions:

• Quantitative Doppler spectrum analysis is a useful noninvasive tool.
• It effectively discriminates between certain causes of decreased renal allograft function.
• This technique aids in the diagnosis of post-transplant kidney complications.