INTRARENAL DUPLEX SONOGRAPHY FOR DETECTING FLOW CHANGES DUE TO RENAL PTA

Purpose: Changes of the intrarenal Doppler signal were analysed before and after renal balloon dilatation to assess the technical success of PTRA. Materials and method: In 33 patients, intrarenal Doppler signal was depicted before and after renal PTA. Doppler flow curve was analysed by using the acceleration index (AI), acceleration time index (AT) and resistance index (RI); for all indices side ratios (AI-R, AT-R and RI-R) were calculated. Balloon dilatation was angiographically successful in all cases. Average stenosis graded 71% before and 21% after PTA. Results: By definition of limits for all indices used, a single patient was graded as non-stenotic before balloon dilatation by application of AI/AI-R and no patient was graded nonstenotic by AI/RI-R. After renal PTA, all indices significantly changed towards normal findings and by application of both AI/AI-R and AI/RI-R, only a single patient Was graded stenotic after PTA. Conclusion: Intrarenal Doppler signal analysis reliably allows to detect flow changes following renal PTA in patients with renal artery stenosis. It may therefore be used as a noninvasive method to monitor now improvement after renal PTA and during follow-up.