Regenerative Medicine-Based Treatment of Stress Urinary Incontinence with Mesenchymal Stem Cells: A Systematic Review and Meta-analysis

Objectives: The aim of this systematic review and meta-analysis is to analyze clinical trials on the use of autologous stem cell [SC] injection for the treatment of stress urinary incontinence [SUI] in humans. Methods: We analyzed the effect in terms of UI improvement and continence recovery after treatment. A literature search was performed following the PRISMA guidelines. Entry into the analysis was restricted to data collected from clinical prospective trials on humans, including female and male patients with SUI. We performed a cumulative meta-analysis to explore the trend in the effect size across different groups at follow-up. Available data were compared in terms of Event Rate [ER] for the percentage of pad-free patients. Results: 12 trials were enclosed in the analysis. The sample size of patients with SUI ranged from 5 to 123 cases, mainly female cases. Autologous muscle-derived stem cells [MDSCs] were used in 9 and adipocyte- derived SCs [ADSC] in 3 trials. Considering a random effect model, ER of continence recovery was 0.41 [95%CI 0.29 - 0.54], with similar results between the ADSC [ER, 0.40;95%CI 0.12 – 0.69] and the MDSC group [ER 0.41; 95%CI 0.27-0.55] [I2 84.69%; Q 104.69 - p<0.01] [Test of group differences p=0.96]. Conclusion: Autologous MDSC or ADSC injection to treat SUI is demonstrated to be a safe procedure and a 41% mean rate of continence recovery is described. A higher effort should be produced to design better clinical trials, objectively evaluating either modifications inside the urethral sphincter or long-term functional results in terms of pad test and UI questionnaires.