Platelet-rich plasma injections for the treatment of Peyronie's disease: a systematic review of contemporary literature with mixed-effects model analysis of penile curvature outcome

BACKGROUND: To provide an updated and detailed overview of the current use of platelet-rich plasma (PRP) penile injections in men affected by Peyronie's disease (PD). METHODS: A comprehensive search in PubMed, Scopus, and Web of Science, was performed for prospective and retrospective, single cohort or comparative studies published in form of full-text articles or conference abstracts, evaluating safety and efficacy of PRP for PD treatment. Primary outcome consisted in the reduction of penile curvature. Sexual function and adverse/side effects were also investigated. Qualitative and quantitative data syntheses were provided. RESULTS: Overall, 15 records were included: four studies focused on PRP alone, two randomized clinical trials tested PRP versus placebo, and the remainder assessed the combination of PRP with external shock wave therapy, manual penile modelling, vacuum erection device therapy, percutaneous needle tunneling, phosphodiesterase type-5 inhibitors or hyaluronic acid. Patient numbers ranged between 10 and 159 according to studies, with 685 patients receiving PRP alone or in combination (median age 56.2 years). Despite the heterogeneity in study design, protocol of administration, dose of PRP, and follow-up duration, all studies independently reported a statistically significant improvement in penile curvature and sexual outcomes, without major adverse/side effects. A linear mixed-effects model was fitted to estimate the change in penile curvature over time across studies, with results suggesting that the effect of PRP on reducing penile curvature tends to improve over time, was enhanced by greater initial treatment intensity, and negatively influenced by patient age. CONCLUSIONS: PRP penile injections for PD treatment have shown encouraging results in preliminary studies. Patient numbers and the short-term follow-up may limit the generalizability of these observations. High-quality, large-scale, and standardized controlled trials are needed before starting to recommend its use in clinical practice.