Comparison of one-side and bilateral intracavernosal papaverine injection on a Doppler study of the penis

Standardization of penile hemodynamic evaluation through color duplex-doppler ultrasound

INTRODUCTION

The vascular evaluation of the erectile function through Color Duplex-Doppler Ultrasound (CDDU) of the penis can benefit the therapeutic decision-making process. Unfortunately, there is no standard procedure for CDDU conduction, a fact that results in high result-interpretation variability.

OBJECTIVE

The aims of this review are to promote greater standardization during CDDU of the penis and discuss the fundamental principles for its accurate conduction.

METHODS

CDDU is initially conducted with the penis in the flaccid state; the whole penis must be assessed (images at B mode) with a high-frequency linear transducer (7.5-18 MHz). Intracavernous injection of vasodilating agents (prostaglandin E1, papaverine, phentolamine) is performed to induce a rigid erection. Serial measurements at different times should be taken during the CDDU session and penile rigidity must be assessed in each evaluation.

RESULTS

It is important to monitor the erection response after the vasoactive agent (hardness scale), and scanning during the best-quality erection should be contemplated. Manual self-stimulation, audiovisual sexual stimulation (AVSS), and vasoactive agent re-dosing protocols must be taken into account to reduce the influence of psychogenic factors and to help the patient to get the hardest erection possible. Such measurements contribute to the maximal relaxation of the erectile tissue, so the hemodynamic parameters are not underestimated.

CONCLUSIONS

CDDU is a relevant specialized tool to assess patients with erectile dysfunction; therefore, this guideline will help to standardize and establish uniformity in its conduction and interpretation, taking into consideration the complexity and heterogeneity of CDDU evaluations of the penis.

Current approaches to the diagnosis of vascular erectile dysfunction

Vascular erectile dysfunction (ED) is closely related to cardiovascular events, and early diagnosis of vascular ED may be helpful to predict the occurrence of cardiovascular events and improve prognosis. At present, there are many approaches to diagnose ED, but each method has its advantages and limitations. This study retrospectively reviewed all available literature focusing on the diagnosis of vascular ED through a systematic PubMed and EMBASE search. According to the different application scenarios, the main methods for the diagnosis of vascular ED are divided into four categories. Intra-cavernous injection of vasoactive drugs is the earliest method used in the diagnosis of vascular ED and is a basic test. For the diagnosis of arterial ED, color duplex Doppler ultrasound, selective penile angiography, magnetic resonance imaging, and computed tomography are more commonly used. While for the diagnosis of venous ED, shear wave elastography, dynamic infusion cavernosometry and cavernosography are more accurate. Endo-peripheral arterial tonometry (PAT) has also been used to detect vascular endothelial function. Although various existing examinations are widely used for the evaluation of vascular ED, they still have some shortcomings, such as invasiveness, contingency, high false positive (negative) rate. New methods of long-term dynamic detection are needed.