Are Radial Pressure Waves Effective in Treating Erectile Dysfunction? A Systematic Review of Preclinical and Clinical Studies

Introduction: Radial waves are used to treat erectile dysfunction; however, they are different than focal waves, and their mechanism of action or effect on improving this condition is not known. Aim: To evaluate the effect of radial waves at the cellular level and their effectiveness at the clinical level for the treatment of erectile dysfunction. Methods: Systematic literature review. Electronic database searches and manual searches were performed to identify (i) clinical trials or cohort studies evaluating the effectiveness of radial waves in men with erectile dysfunction and (ii) preclinical trials in animal models or cell cultures in which the production of nitric oxide or endothelial growth factor was evaluated. Study quality was assessed, and data were extracted from each study. A narrative synthesis of the results was performed given the high heterogeneity between the selected studies. Main outcomes measures: Nitric oxide production, endothelial growth factor expression, and changes in the Erection Hardness Score (EHS) and the International Index of Erectile Function (IIEF) Questionnaire score. Results: Four studies in animal models and 1 randomized clinical trial in men with erectile dysfunction and kidney transplantation were identified that met the selection criteria. Preclinical studies in animals suggest that radial waves increase cellular apoptosis in penile tissue, while vascular endothelial growth factor expression increases in brain tissue. In men with erectile dysfunction, no differences were found between radial wave therapy and placebo therapy in the mean IIEF score (15.6 +/- 6.1 vs 16.6 +/- 5.4 at 1 month after treatment), EHS (2.5 +/- 0.85 vs 2.4 +/- 0.7 at 1 month after treatment), or penile Doppler parameters. Conclusions: No quality evidence was found to support the use of radial waves in humans for the treatment of erectile dysfunction. In animal models and at the cellular level, the results are contradictory. More research is needed. Copyright (C) 2021 The Authors. Published by Elsevier Inc. on behalf of the International Society for Sexual Medicine.