Renal artery stenosis: duplex US after angioplasty and stent placement.

Abstract

To evaluate the hemodynamic outcome of technically successful percutaneous transluminal renal artery angioplasty and stent placement (PTRAS) with duplex ultrasonography (US). Eighteen patients who underwent PTRAS in 22 renal arteries were prospectively examined. All had abnormal preprocedural duplex US findings. Those who had significant renal artery stenosis (>70%) at angiography and underwent technically successful percutaneous interventions were enrolled. Standard intrarenal duplex US parameters (acceleration index [AI], acceleration time, waveform morphology grade, and resistive index) were compared before and after interventions. A significant AI increase occurred after PTRAS (9.02 m/sec(2) +/- 4.85 [SD]), as compared with before intervention (2.34 m/sec(2) +/- 2.03; P <.001). Acceleration time significantly decreased from 0.084 second +/- 0.049 to 0.032 second +/- 0.008 (P <.01). There was also a significant resistive index increase from 0.69 +/- 0.12 to 0.79 +/- 0.12 (P <.01). Abnormal waveform morphology (modified Halpern waveform grade 3-6) was present in 19 (86%) of 22 intrarenal arteries prior to intervention, as compared with one (5%) after PTRAS (P <.001). In the instance in which an abnormal waveform persisted after intervention, waveform morphology improved from grade 6 to grade 3, with a concomitant AI increase from 0.96 to 5.1 m/sec(2). The findings suggest an important potential role for duplex US in noninvasive assessment of the immediate hemodynamic outcome and long-term follow-up of PTRAS.