Evaluating Different Low-intensity Extracorporeal Shockwave Therapy Intensities in the Treatment of Peyronie's Disease in a Rat Model

Abstract

ABSTRACT Introduction Low-intensity extracorporeal shockwave therapy (Li-ESWT) is postulated to have physiologic effects including neo-angiogenesis, upregulation of vasoactive endothelial growth factors, nerve recovery, reduction of fibrotic changes, cavernosal tissue remodeling, and reduction in sympathetic tone. To date, randomized clinical trials have failed to demonstrate a change in penile curvature, with mixed results on erectile function, in Peyronie's disease (PD) patients. Objective To evaluate the treatment effect of Li-ESWT for amelioration of PD-associated fibrosis and PD-associated erectile dysfunction using a rat model of PD. Methods 32 adult male Sprague-Dawley rats were divided evenly into four groups: sham (S), control (T), low setting Li-ESWT (TL), and high setting Li-ESWT (TH). Normal saline was injected into the tunica albuginea (TA) of the sham group. Transforming growth factor beta-1 (TGF-B1) was injected into the TA of the remaining groups to induce Peyronies-like fibrosis. After 5 weeks of TGF-B1 induction, treatment with Li-ESWT shockwave (UroGold 100™) was initiated. Treatment was delivered biweekly for 3 weeks (6 total sessions). Device settings were 600 shocks at 3 Hz, at level 6 (0.093 mJ/mm2) for the Low group and at level 12 (0.125 mJ/mm2) for the High group. Two weeks after the end of treatment, erectile function was measured by ratio of intracavernosal pressure (ICP) to mean arterial pressure (MAP). Histological analysis by H&E and Trichrome staining was performed. Western blot analysis of Collagens I (COL1A1), III (COL3A1), elastin, alpha-smooth muscle actin (a-SMA), and TGF-B1 was performed. Results There was no significant difference demonstrated in erectile function between T control group and TL and TH groups (P > 0.05). However, there seems to be a trend in decreased amount of fibrosis upon examination of the prepared histologic sections. Animals in the TL and TH groups had decreased COL1A1, COL3A1, elastin, and TGF-B1 expression in the TA compared to the T group. a-SMA expression in the treatment groups was found to be increased compared to both S and T groups. Conclusions Our preliminary data shows that Li-ESWT treatments, at different intensities, may decrease fibrosis induced by TGF-B1 TA injections. Additionally, Li-ESWT was not found to have conclusive positive effects on erectile function. Disclosure Yes, this is sponsored by industry/sponsor: Sexual Medicine Society of North America Clarification Industry funding only - investigator initiated and executed study Any of the authors act as a consultant, employee or shareholder of an industry for: Endo Pharmaceuticals