The Penile Duplex Ultrasound: how and when to perform it?

Because it is a superficial structure, the penis is ideally suited to ultrasound imaging. A number of disease processes, including Peyronie's disease, penile fractures and tumors, are clearly visualized with ultrasound. Baseline and dynamic assessment of cavernosal arterial changes after pharmaco-stimulation with alprostadil allows standardized diagnosis of arterial and venogenic causes of erectile dysfunction (ED).

to illustrate how to correctly perform flaccid and dynamic penile duplex ultrasound (D-PDU) and in which patients to recommend it.

An extensive search of the literature was carried out on Pubmed with the insertion of the following Medical Subjects Headings (MeSH) termsand keywords "penile color doppler ultrasound" "peak systolic velocity" "end diastolic velocity", "acceleration time", "resistance index".

In our experience, arterial erectile dysfunction is identified after standardized intracavernous injection (ICI) of alprostadil (10 mcg) when values ​​of peak systolic velocity (PSV) are <35 cm / sec and, in the most severe forms, for values ​​<25 cm / sec. Arterial insufficiency can also be identified by increased acceleration time (AT) values (>110 msec) and/or by a lack of visualization of helicine arteries at power-doppler mode along with incomplete achievement of penile rigdity. The veno-occlusive incompetence is determined when end diastolic velocity (EDV) values are > 4.5-5 cm / sec or in the case of resistance index (RI) values ​​<0.75. The assessment of additional surrogate markers of endothelial dysfunction, i.e. intima-media thickness, mean platelet volume (MPV), endothelial progenitor cells (EPC), endothelial cell specific molecule-1(endocan) are also useful in assessing the patient's cardiovascular risk but are still considered investigational in the interpretation of D-PDU results.

D-PDU scan after ICI with vasoactive drugs is a safe procedure and represents the gold standard for the diagnostics of penile pathologies and should be performed in men with ED not responding to oral conventional therapies and/or in those requiring accurate stratification of cardiovascular risk.

Andrology. 2021 May 06 [Epub ahead of print]

Antonio Aversa, Andrea Crafa, Emanuela Alessandra Greco, Eusebio Chiefari, Antonio Brunetti, Sandro La Vignera

Department of Experimental and Clinical Medicine, University "Magna Graecia", Catanzaro, Italy., Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy., Department of Health Sciences, University "Magna Graecia", Catanzaro, Italy.