Value of doppler ultrasound hemodynamics in the assessment of renal artery stenosis in transplanted kidneys : an assessment of patients after percutaneous transluminal angioplasty

Doppler ultrasound (USS) may allow a non-invasive early diagnosis of transplant renal artery stenosis (TRAS). Adequate Doppler sampling of the transplant renal artery is difficult, time consuming and highly operator dependent. As a result, there has been increased attention focused on the intrarenal vessels and downstream changes that occur secondary to TRAS. We evaluated Doppler USS parameters in nine patients with TRAS confirmed on angiography (significant stenosis defined as > 60 % diameter narrowing). Doppler USS correctly identified all the nine stenoses. Mean peak systolic velocity (PSV) was 3.6 m / s + 1.09. Mean end-diastolic velocity (EDV) was 1.75 m /s + 0.25 with an acceleration time (AT) of 0.14 + 0.04 sec and resistivity index (RI) of 0.42 + 0.12. Early systolic peak (ESP) was lost in all cases. Percutaneous transluminal angioplasty (PTA) was successfully done in five patients with significant improvement in Doppler parameters. PSV decreased from 4.04 m /s + 1.35 to 0.76 m / s + 0.42 (p = 0.01). Similarly EDV improved from 1.71 m / s + 0.28 to 0.30 m / s + 0.17 (p = 0.001). AT improved from 0.13 + 0.01 to 0.05 + 0.01 sec (p = 0.001). RI normalized from 0.34 + 0.07 to 0.73 + 0.09 (p = 0.008). ESP was restored in all the patients. In conclusion : our results show that the Doppler USS analysis of segmental arteries is an excellent tool for the diagnosis of TRAS and follow-up of patients post PTA.