Regenerative treatment with platelet-rich plasma in patients with refractory erectile dysfunction: short-term outcomes and predictive value of mean platelet volume.

Background: The vast majority of erectile dysfunction (ED) treatments are currently symptomatic and do not influence disease progression. Regenerative medicine may potentially reverse or stop the progression of complicated ED by restoring erectile capacity. We aimed to evaluate potential safety and effectiveness and the clinical correlates of platelet function before platelet-rich plasma (PRP) injection in men with vascular ED unresponsive to phosphodiesterase-5 inhibitors (PDE-5is).

Methods: A number of 150 patients with vascular ED were enrolled in an open-label, single arm, multicenter, prospective, interventional, non-randomized study. After 1-month pharmacological washout from PDE-5is, the 5-item International Index of Erectile Function (IIEF-5) questionnaire was administered and dynamic penile duplex ultrasound (d-PDU) was performed. Patients then underwent intracavernous PRP injection. One month after treatment, IIEF-5 and d-PDU were evaluated. Primary aim of the study was to assess efficacy and safety of PRP treatment by evaluating the proportion of patients achieving minimal clinically important differences (MCID) in the IIEF-5 questionnaire. Secondary endpoint was to determine whether MPV could correlate with improvement in d-PDU parameters.

Results: Most patients (80%) had a significant improvement in ED symptoms (IIEF-5 Score: 12±2.6 vs. 19±3.0; P<0.0001) and in PSV (32±3.5 cm/s vs. 42±7.6 cm/s; P<0.0001) after d-PDU evaluation. The ROC curve analysis showed a significant accuracy (72.1%, CI: 64.0-80.2, P≤0.0001) for MPV in identifying men clinically responding to PRP with favorable MCID≥5 at 1 month follow-up. The MPV<8.95 fL was identified as the best predictor of success rate with a sensitivity of 90% and a specificity of 54.1%.

Conclusions: This study provides the first evidence that PRP could represent an effective and safe option for patients poorly responding to PDE-5is. MPV higher than 8.95 fL may identify patients with poor response to treatment that might benefit of successive re-challenge with PRP.