Regenerative therapies for erectile dysfunction: a systematic review, Bayesian network meta-analysis, and meta-regression.

Background: Current guidelines advocate a shared decision-making process approach to erectile dysfunction management, and while there is growing interest in regenerative therapies such as stem cell therapy, platelet-rich plasma injections, and low-intensity shockwave therapy for erectile dysfunction, comparative data on the efficacy of these modalities are limited.

Aim: This systematic review and network meta-analysis aims to compare stem cell therapy, platelet-rich plasma injections, and low-intensity shockwave therapy for managing erectile dysfunction and quantify their impact on the International Index of Erectile Function (IIEF).

Methods: In January 2024, a systematic search of online databases was performed to identify randomized clinical trials related to stem cell therapy, platelet-rich plasma injections, and low-intensity shockwave therapy in erectile dysfunction. Eligible articles reported outcomes using the IIEF score. Data were inputted into Review Manager 5.4 for pairwise meta-analysis. Data were then used to build a network in R Studio. These networks were used to model 200 000 Markov Chains via MonteCarlo sampling. The results are expressed as standardized mean difference (SMD) with 95% credible intervals (CrI). Meta-regression was used to adjust for PDE5is use.

Outcomes: Impact on the International Index of Erectile Function.

Results: A total of 16 studies involving 907 patients were analyzed. The standardized mean difference (SMD) vs control for stem cell therapy was 0.92 [95% CrI -0.49, 2.3]. For platelet-rich plasma, the SMD vs control was 0.83 [95% CrI 0.15, 1.5], and for low-intensity shockwave therapy, the SMD vs control was 0.84 [95% CrI 0.49, 1.2]. When stratifying low-intensity shockwave therapy by dose, the SMD vs control at 0.15 mJ/mm2 was 1.1 [95% CrI 0.36, 1.9], while at 0.09 mJ/mm2, it was 0.75 [95% CrI 0.26, 1.2]. Meta-regression adjusting for the administration of PDE5 inhibitors yielded non-significant results.

Clinical implications: The findings suggest that stem cells, platelet-rich plasma, and low intensity shockwave therapy, particularly at 0.15 and 0.09 mJ/mm2, may offer improvements in erectile function.

Strengths and limitations: The strength is the robust statistical methods. Limitations are in heterogeneity in control groups and follow-up durations among included studies.

Conclusion: Shockwave therapy and platelet-rich plasma demonstrated statistically significant improvements, though the clinical relevance and extent of their impact remain questionable. Further research is necessary to determine the efficacy of stem cell therapies for erectile function.