Randomized trial of low intensity shockwave therapy for erectile dysfunction utilizing grayscale ultrasound for analysis of erectile tissue homogeneity/inhomogeneity.

Background: Electrohydraulic shockwave devices have been Food and Drug Administration-cleared for improved blood flow and connective tissue activation and have been used to treat erectile dysfunction (ED). In this study, the main focus was to evaluate improvement in erectile tissue quality after low intensity shockwave therapy (LiSWT). Methods: A single-blind, sham-controlled, randomized, prospective study, was performed in men with ED naïve to shockwave or radial ballistic pressure wave therapy. Participants were randomized 1:2 to simulated (sham) or active LiSWT treatment. After simulated treatments, participants in the Sham Arm were converted to active LiSWT, while participants initially in the Active Treatment Arm received no further treatment. Assessments were performed at baseline and two follow-up visits. Subjective parameters of erectile function (EF) were assessed by total and EF domain scores of the International Index of Erectile Function (IIEF) and sexual encounter profile (SEP). Objective parameters of penile erection were measurements of hypoechoic areas in images obtained by grayscale ultrasound (GUS) with high resolution 15.4 MHz probe and cavernosal artery peak systolic velocity (PSV) and end diastolic velocity (EDV) by color duplex Doppler ultrasound (DUS). Outcome measures for erectile and urinary function were also obtained. Results: Simulated LiSWT did not significantly change any assessment parameter. Sham Arm participants who converted to active LiSWT had significantly increased mean IIEF total (P=0.02) and IIEF-EF scores that approached statistical significance (P=0.06), relative to baseline. Similarly, at the end of the study, Active Treatment Arm participants had significantly increased mean IIEF total (P=0.02) and IIEF-EF scores that approached statistical significance (P=0.07), relative to baseline. Additionally, at the end of the study, SEP3 success rates (erection lasting long enough for successful intercourse) approached statistical significance when Sham Arm participants were converted to active LiSWT (P=0.08) and reached statistical significance in the Active Treatment Arm (P=0.049). GUS assessments by visual grading were significantly correlated to IIEF-EF score (P=0.002) and were significantly increased relative to baseline in the Active Treatment Arm at follow-up Assessment 1 (P=0.03) and Assessment 2 (P=0.04). The greatest reduction in hypoechoic area after LiSWT occurred in the proximal penile shaft. EDV was also significantly reduced in the Active Treatment Arm at follow-up Assessment 1 (P=0.04) and Assessment 2 (P=0.04). LiSWT also resulted in improved prostate symptom scores, approaching significance in the Active Treatment Arm (P=0.055) with no changes in prostate-specific antigen. Treatment-related adverse events were limited and transient. Conclusions: In this prospective trial, LiSWT was safe and efficacious for erectile symptoms using GUS imaging as a novel, non-invasive method to assess improvements in corporal veno-occlusive function. Improved veno-occlusion and reduced hypoechoic area demonstrated by GUS imaging suggest that LiSWT decreases connective tissue content in penile erectile tissue. Lower urinary tract symptoms also improved with LiSWT. Trial Registration: NCT06600893 on clinicaltrials.gov.