Stress urinary incontinence and regenerative medicine: is injecting functional cells into the urethra feasible based on current knowledge and future prospects?

Cell Therapy in the Treatment of Female Stress Urinary Incontinence: Current Status and Future Proposals

BACKGROUND

Stress urinary incontinence (SUI) is a common condition with a significant impact on the quality of life of female patients. The limitations of current treatment strategies have prompted the exploration of new effective and minimally invasive alternative approaches, including cell therapy.

METHODS

A literature search was conducted to update the current clinical status of stem cell therapy in the management of female stress urinary incontinence.

RESULTS

Over thirty clinical studies have been designed to assess the feasibility, safety and efficacy of cell therapy for female SUI. Despite differences in cell types and protocols, the overall treatment procedures were similar. Standard subjective and objective assessment tools, and follow-up periods ranged from 6 weeks to 6 years have been used. Cell injection has shown to be a safe therapy in the treatment of female SUI. However, the results from more recent randomized trials have shown less promising results than expected in restoring continence. Heterogeneous research methodologies using different cell types and doses make it difficult to draw conclusions about effectiveness. Several key points remain that need to be further explored in future clinical trials.

CONCLUSION

To advance in the development of cell therapy, it is essential to know the mechanisms involved to be able to direct it properly, its efficacy and the durability of the injected cells. Rigorous and homogenized preclinical and clinical studies that demonstrate its scope and improve its application are necessary for validation in the treatment of female SUI.

Suburethral implantation of autologous regenerative cells for female stress urinary incontinence management: Results of a pilot study

OBJECTIVES

To assess the feasibility and the safety of treating female stress urinary incontinence (SUI) with suburethral implantation of a mixture of the stromal vascular fraction from adipose tissue and leukocyte-and platelet-rich-fibrin.

METHODS

Patients with SUI were treated with a mixture of stromal vascular fraction and leukocyte-and platelet-rich fibrin. The stromal vascular fraction was obtained from enzymatic digestion of autologous adipose-tissue and added to an leukocyte-and platelet-rich-fibrin membrane. The mixture was transvaginally implanted into the suburethral area. A fraction of the Stromal vascular fraction sample was used for cellular characterization. Patients were followed for 9 months. Every 3 months, the patients were clinically evaluated with a cough- stress test and a validated-questionnaire. An MRI was performed preoperatively and 3 months after the procedure to assess tissue changes.

RESULTS

Ten patients received the surgical procedure. The validated-questionnaire revealed a subjective SUI improvement in nine patients 3 months after the operation and in seven patients 9 months after the operation. Eight, six, and four patients achieved a negative cough-stress test 3, 6 and 9 months post-injection, respectively. Flow cytometric analysis of stromal vascular fraction cell phenotypes revealed predominantly mesenchymal and endothelial cell heterogeneity. In total, we injected 0,18 × 10⁶ to 13,6 × 10⁶ cells. No adverse events were observed peri- or postoperatively.

CONCLUSION

These preliminary results suggest that the suburethral implantation of a combination of SVF and l-PRF is a feasible and safe modality for treating female SUI. However, evidence is lacking and further research are needed to clarify the respective roles of SVF and l-PRF in female SUI treatment.

Long-term effects of muscle-derived stem cell therapy on the regeneration of the urethra of female rats

INTRODUCTION AND HYPOTHESIS

The aim was to analyze the long-term effects of muscle-derived stem cells (MDSCs) therapy in traumatized urethras of female rats regarding messenger ribonucleic acid (mRNA) expression of collagens 1 and 3, Ngf and Ki67; and the mRNA and protein expression of Myh11 and Myh2.

METHODS

Muscle-derived stem cells were injected into the tail vein of rats 3 days after trauma by vaginal distention. Urethras were analyzed from 30 animals divided into three groups: control without injury or treatment, trauma (30 days post-injury), and MDSC (30 days post-injury who received MDSC therapy). Real-time quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry were performed. The Kruskal-Wallis and ANOVA tests were used with p < 0.05 indicating significance.

RESULTS

We detected increased Myh11 and Myh2 mRNA expression in the trauma group compared with the control group (p = 0.03 and p = 0.04 respectively). Ki67 and Col1a1 genes were overexpressed in the MDSC group compared with both the trauma (p = 0.02 and p = 0.008 respectively) and the control group (p = 0.01 and p = 0.03 respectively). Col3a1 gene was upregulated in the MDSC compared with the control group (p = 0.03). Ngf mRNA level was lower in the MDSC group than in the trauma group (p = 0.002). Myh11, Myh2, and Desmin proteins were overexpressed in the MDSC compared with the trauma group (1.5-fold, p = 0.01; 1.5-fold, p = 0.04; 1.3-fold, p = 0.01 respectively).

CONCLUSIONS

Muscle-derived stem cell therapy may have had long-term structural and molecular effects on the injured urethra of female rats, particularly on markers of cell proliferation, neural growth factor, extracellular matrix, and muscle content. This study suggests that MDSC therapy acted mainly to produce urethral sphincter regeneration marked by increased immunohistochemical expression of the proteins desmin, smooth muscle Myh11, and skeletal muscle Myh2.

Cell Technologies in the Stress Urinary Incontinence Correction

The scientific literature of recent years contains a lot of data about using multipotent stromal cells (MSCs) for urinary incontinence correction. Despite this, the ideal treatment method for urinary incontinence has not yet been created. The cell therapy results in patients and experimental animals with incontinence have shown promising results, but the procedures require further optimization, and more research is needed to focus on the clinical phase. The MSC use appears to be a feasible, safe, and effective method of treatment for patients with urinary incontinence. However, the best mode for application of cell technology is still under study. Most clinical investigations have been performed on only a few patients and during rather short follow-up periods, which, together with an incomplete knowledge of the mechanisms of MSC action, does not make it possible for their widespread implementation. The technical details regarding the MSC application remain to be identified in more rigorous preclinical and clinical trials.