Penile low intensity shock wave therapy for PDE5I non-responders: A prospective, randomized, placebo-controlled study

Objective: Several animal and human studies have evaluated the role of low-intensity extracorporeal shockwave therapy (LIST) in the management of multiple disorders. Recently, some studies with contradictory results have assessed the efficacy and safety of this therapy on patients suffering erectile dysfunction. The aim of the study is to investigate the effects of penile LIST on erectile function in patients suffering erectile dysfunction refractory to phosphodiesterase type 5 inhibitors (PDE5i). Methods: Prospective, randomized, simple-blind, shamcontrolled study. Fifty-eight patients with vasculogenic erectile dysfunction refractory to PDE5i were randomized into two groups. 30 were treated with electrohydraulic low intensity shock waves (1 session/week for 6 weeks; 1,500 pulses of 0.10 mJ/mm2 at 5 Hz) and 28 were treated with a sham probe. Eleven patients withdrew from the study and were lost to follow-up. All patients were evaluated at baseline and 1 month after the end of treatment using validated erectile dysfunction questionnaires. Results: 27 active-treated patients and 20 sham-treated patients completed the one-month follow-up. There was no significant difference between baseline characteristics. Baseline five-item version of the International Index of Erectile Function (IIEF-5) mean scores, in the active and sham groups, were 10.0 ± 3.9 and 10.0 ± 4.5, respectively (p=0.863). At baseline, 48.1% of patients in the active group and 50.0% of patients in the placebo group had a positive answer to the Sexual Encounter Profile (SEP) 2 question (p=1.000); 11.1% of patients in the active group and 10.0% of patients in the placebo group had a positive answer to the SEP 3 question (p=1.000). One month after treatment IIEF-5 scores mean changes from baseline, in the active and placebo group, were 1.6 ± 4.7 and 0.5 ± 4.4, respectively (p=0.478). SEP 3 positive responders increased by 18.5% in the active group and by 0% in the placebo group (p=0.063). Conclusion: In this specific sample, electrohydraulic LIST produced non-significant changes in erectile function at one-month follow up, compared to sham treated patients. Type of energy, intensity, frequency of shockwaves and follow-up length, together with limited sample size, could be in part responsible for this finding. More studies with larger sample size and longer follow-up, comparing different lithotripters and shock wave protocols, are imperative to elucidate the real role of LIST in erectile dysfunction.