Penile duplex pharmaco-ultrasonography revisited: Revalidation of the parameters of the cavernous arterial response

Purpose: We revalidate parameters of the cavernous arterial response (peak systolic blood flow velocity) and acceleration time using penile duplex pharmaco-ultrasonography. Materials and Methods: Blood flow velocity in the cavernous artery following pharmaco-stimulation was determined with duplex ultrasonography in 106 patients with erectile dysfunction. Intima media thickness of the common carotid artery, a valid index for atherosclerosis and clinical diagnosis based on a comprehensive evaluation were used as references. The clinical diagnosis was used to determine cutoff values. For the statistical analysis, Pearson correlation and ROC curves were used. Results: When correlating peak systolic velocity and acceleration time to intima media thickness, acceleration time (r = 0.51, p <0.01) was the most valid parameter to detect cavernous atherosclerotic pathology (peak systolic velocity r = -0.18, p = 0.12). This finding was confirmed by a comparison of both parameters to the clinical diagnosis. AUC was 0.59, 95% CI 0.49-0.69 for peak systolic velocity and 0.72 (95% CI 0.62-0.80 for acceleration time). The cutoff point for acceleration time to discriminate between atherosclerotic and nonatherosclerotic erectile dysfunction was determined at acceleration time 100 milliseconds or greater. Sensitivity was 66% and specificity was 71%. Conclusions: The results of this study show that acceleration time has more power than peak systolic velocity to diagnose atherosclerotic erectile dysfunction.