Commentary to low-energy shock wave therapy ameliorates erectile dysfunction in a pelvic neurovascular injuries rat model, published in J Sex Med 2016;13:22-32 by Li H, Matheu P, Sun F, et al.
Low-energy shockwaves (LESW) have been widely used to treat musculoesketal disorders and the therapeutic application of this technology is currently expanding to treat vasculogenic erectile dysfunction (ED) of varying severity and different etiologies, and also ischemic heart disease. In 2012 a working group reported results better than placebo for LESW in patients with ED (1). Since then numerous scientific papers evaluating or reviewing the effect of this treatment with various generating devices have been published. Several randomized trials are currently ongoing and a recent systematic review and meta-analysis confirms treatment with LESW for ED is effective, both in the short and medium term to assess efficacy based on the change in the International Index of Erectile Function (IIEF-EF) (2). Also this review confirms LESW is more effective than placebo in the short term; however to evaluate long-term efficacy data appear still insufficient. Well-designed prospective blind studies are still not abundant. What is worse, it must be admitted that good-quality experimental studies to explain the role of this therapy according to specific causes of ED are also needed.
The fundamental reason that explains the mode of action of therapeutic ultrasound is based on the cellular microtrauma and cavitation caused promote revascularization through recruitment of endothelial progenitor cells (3,4). Young and Dyson were the first to demonstrate that therapeutic ultrasound promotes angiogenesis by enhancing the expression of vascular endothelial growth factor (VEGF) (5). Likely this mechanism has potential in the treatment of coronary artery disease and other processes such as diabetic ulcers, calcifying tendinitis and fracture healing application, and could explain some therapeutic role in vasculogenic ED (6). Animal studies have also shown neoangiogenesis in tissue flaps and skin infarction (7). Before accepting the widespread use of this non-invasive treatment for ED more solid clinical and experimental data should be wellcome.
A very innovative article on the field has been recently published (8). A rat model of pelvic neurovascular injury proves that LESW therapy improves erectile function by leading to angiogenesis, tissue restoration and nerve regeneration through activation of Schwann cells, and also that Schwann cell activation markers appear upregulated after LESW treatment (8). The coincidence of nerve regeneration with angiogenesis and Schwann cell activation opens a new perspective to get to know the mode of action of shock waves in patients with ED. We do not know if this mechanism of peripheral nerve regeneration is present in all patients responding to this treatment. Once this question is answered the search for a marker of response will follow and that will be welcome by clinicians and therapists (9).
Only randomized multicentric clinical trials, some of them ongoing and many others still not conducted, will give final light upon the clinical benefit of LESW and especially on patient selection and the optimum therapeutic schedule and dose on the particular patient.
Acknowledgements
None.
Footnote
Conflicts of Interest: The author has no conflicts of interest to declare.
References
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- Li H, Matheu MP, Sun F, et al. Low-energy Shock Wave Therapy Ameliorates Erectile Dysfunction in a Pelvic Neurovascular Injuries Rat Model. J Sex Med 2016;13:22-32. [Crossref] [PubMed]
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