(641) Inclusion of the Crus in Assessment of Low Intensity Shockwave Therapy for Erectile Dysfunction

Introduction A previous double-blind, sham controlled clinical trial showed on grayscale ultrasound that low intensity shockwave therapy (LiSWT) can improve erectile homogeneity in the penile shaft. It is hypothesized that LiSWT mechanotransduction stimulates mesenchymal stem cells to eventually increase cavernosal smooth muscle cells, thereby improving smooth muscle to connective tissue ratio, theoretically the reason for erectile tissue and function improvement. Objective This study examines preliminary data focusing on the crus rather than the penile shaft. Methods A retrospective chart review was performed of patients who had undergone baseline penile Grayscale/Doppler ultrasound (G/DUS), were treated with LiSWT (Urogold 100 MTS) where a majority of the shockwaves were applied to the crus rather than the penile shaft and had a follow-up G/DUS <6 months after the last shockwave treatment. B-mode ultrasound (Aixplorer 15.4 MHz transducer) is performed during erection at specific settings to avoid reader bias. For crural ultrasound the patient is supine with legs placed in frog leg position. A rolled sheet placed under the scrotum allows access to the crus. The transducer is placed horizontally in the ventral position to identify the corpus spongiosum and midline. The probe is moved inferiorly to identify where the corpora spongiosum becomes the central structure and the 2 corpora cavernosa move laterally. Axial images are taken at a fixed dynamic range of 70 dB with B-mode gain values of increased brightness (45%, 55%, 65%). The fourth image at each axial location is taken at a dynamic range of 49 dB and a B-mode gain value identified as providing the best discrimination between Grayscale black/white. Sets of 5 or 6 LiSWT treatments were administered over varying intervals using a parabolic reflector probe (OP-155), energy flux density 0.13mJ/mm2, 3 Hz, applied each to the right and left erect crura (total shocks ≥ 1600). Homogeneity/inhomogeneity on GUS was assessed in the right and left crura as no inhomogeneity, mild (<25% of cross-sectional area revealing hypo- or hyper-echoic regions), moderate (25% - 50%), or severe inhomogeneity (>50%). Results There was no statistically significant decrease of inhomogeneity between baseline and post treatment grayscale measurements when looking at mean values (n=31) individuals (Figure 1), but separating the population into young men, ≤45 years old at presentation, (n=15) and older (n=16), revealed a trend for improvement in the younger population. This study did not focus on etiology of ED, which may have a bearing on treatment results. Baseline inhomogeneity was significantly worse in the older population (Figure 2). When looking at individual results, however, 10 of the 31 (32%) showed improvement of the crus after treatment. Conclusions LiSWT can be an effective treatment for ED, however more research is needed regarding focusing additional shockwaves to the crus to improve the health of that tissue. In individual cases this strategy has successfully reversed inhomogeneity. Likely there are multiple pathologies resulting in ED, including local blunt trauma which occurs more often in the younger population and may require significantly more treatment to the crus to counteract the damage, and cardiovascular disease which is an ongoing process with aging. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Softwave/MTS