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

Abstract

We revalidate parameters of the cavernous arterial response (peak systolic blood flow velocity) and acceleration time using penile duplex pharmaco-ultrasonography. 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. 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%. The results of this study show that acceleration time has more power than peak systolic velocity to diagnose atherosclerotic erectile dysfunction.