State of the art of where we are at using stem cells for stress urinary incontinence

Transurethral injection of autologous muscle precursor cells for treatment of female stress urinary incontinence: a prospective phase I clinical trial

INTRODUCTION AND HYPOTHESIS

The purpose was to investigate the safety and feasibility of transurethral injections of autologous muscle precursor cells (MPCs) into the external urinary sphincter (EUS) to treat stress urinary incontinence (SUI) in female patients.

METHODS

Prospective and randomised phase I clinical trial. Standardised 1-h pad test, International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form (ICIQ-UI-SF), urodynamic study, and MRI of the pelvis were performed at baseline and 6 months after treatment. MPCs gained through open muscle biopsy were transported to a GMP facility for processing and cell expansion. The final product was injected into the EUS via a transurethral ultrasound-guided route. Primary outcomes were defined as any adverse events (AEs) during follow-up. Secondary outcomes were functional, questionnaire, and radiological results.

RESULTS

Ten female patients with SUI grades I-II were included in the study and 9 received treatment. Out of 8 AEs, 3 (37.5%) were potentially related to treatment and treated conservatively: 1 urinary tract infection healed with antibiotics treatment, 1 dysuria and 1 discomfort at biopsy site. Functional urethral length under stress was 25 mm at baseline compared with 30 mm at 6 months' follow-up (p=0.009). ICIQ-UI-SF scores improved from 7 points at baseline to 4 points at follow-up (p=0.035). MRI of the pelvis revealed no evidence of tumour or necrosis, whereas the diameter of the EUS muscle increased from 1.8 mm at baseline to 1.9 mm at follow-up (p=0.009).

CONCLUSION

Transurethral injections of autologous MPCs into the EUS for treatment of SUI in female patients can be regarded as safe and feasible. Only a minimal number of expected and easily treatable AEs were documented.

Stress urinary incontinence in females. Diagnosis and treatment modalities – past, present and the future

Introduction:

Stress urinary incontinence (SUI) can be defined as involuntary and unintentional loss of urine through the urethra when vesical pressure exceeds the urethral sphincter pressure during instances of coughing, sneezing or physical exercise. Stress urinary incontinence is the most common form of incontinence in females with an estimated prevalence of 4.5–53% in adult women with urinary incontinence. Yet despite its distressing nature and a negative impact on quality of life, very few women present with their symptoms to a urologist.

Materials and methods:

A literature search of the MEDLINE, Cochrane Library, Embase, NLH, ClinicalTrials.gov and Google Scholar databases was done up to November 2020, using terms related to SUI, medical therapy, surgical therapy and treatment options. The search terms included female stress urinary incontinence, mid-urethral sling, tension-free vaginal tape and trans obturator tape. The search included original articles, reviews and meta-analyses.

Conclusion:

Current guidelines for the management of stress urinary incontinence propose a step-ladder pattern, based on treatment invasiveness starting from conservative therapies, then drugs followed by minimally invasive procedures and culminating in invasive surgeries. The surgical approach is to be considered only after conservative therapies fail. The recent advances in the treatment of stress urinary incontinence have brought to light newer modalities and newer technologies that can be utilized which include laser therapy, stem cell therapy, intravesical balloon and others that show a lot of promise. This paper provides an in-depth analysis and reviews the literature on the current modalities and the future prospects of female stress urinary incontinence.

Level of evidence:

Not applicable for this review article.

Treatment of Stress Urinary Incontinence with Muscle Stem Cells and Stem Cell Components: Chances, Challenges and Future Prospects

Urinary incontinence (UI) is a major problem in health care and more than 400 million people worldwide suffer from involuntary loss of urine. With an increase in the aging population, UI is likely to become even more prominent over the next decades and the economic burden is substantial. Among the different subtypes of UI, stress urinary incontinence (SUI) is the most prevalent and focus of this review. The main underlying causes for SUI are pregnancy and childbirth, accidents with direct trauma to the pelvis or medical treatments that affect the pelvic floor, such as surgery or irradiation. Conservative approaches for the treatment of SUI are pelvic physiotherapy, behavioral and lifestyle changes, and the use of pessaries. Current surgical treatment options include slings, colposuspensions, bulking agents and artificial urinary sphincters. These treatments have limitations with effectiveness and bear the risk of long-term side effects. Furthermore, surgical options do not treat the underlying pathophysiological causes of SUI. Thus, there is an urgent need for alternative treatments, which are effective, minimally invasive and have only a limited risk for adverse effects. Regenerative medicine is an emerging field, focusing on the repair, replacement or regeneration of human tissues and organs using precursor cells and their components. This article critically reviews recent advances in the therapeutic strategies for the management of SUI and outlines future possibilities and challenges.

Stem cell applications in regenerative medicine for stress urinary incontinence: A review of effectiveness based on clinical trials

Objective

To evaluate the current state, therapeutic benefit and safety of urethral injection of autologous stem cells for the treatment stress urinary incontinence (SUI).

Materials and methods

A selective database search of PubMed, the Excerpta Medica dataBASE (EMBASE), Cochrane Library and Google Scholar was conducted to validate the effectiveness of stem cell-based therapy. The search included clinical trials published up until 4 January 2020, written in English, and included cohorts of women and men who had received stem cell-based therapy for SUI. The search used the following keywords in various combinations: ‘stem cell therapy’, ‘cell-based therapy for SUI’, ‘regenerative medicine for SUI’, and ‘tissue engineering’. The success rates were assessed according to cough test, urodynamics, pad tests, and International Consultation on Incontinence Questionnaire-Urinary Incontinence. The primary endpoint was continence rate to measure objectively the effect of the treatment.

Results

We identified four clinical trials using local injections of adipose-derived stem cells (ADSCs), 11 trails with muscle-derived stem cells (MDSCs), and two trails with human umbilical cord blood stem cells (HUCBs) and total nucleated cells (TNCs). The median improvement rate of intrinsic sphincter deficiency after ADSCs, MDSCs, TNCs, HUCBs injections were 88%, 77%, 89%, 36% (improvement rate: 1–2 pads) at a mean (range) follow-up of 6 (1–72) months. The cell sources, methods of cell processing, cell number, and implantation techniques differed considerably between studies. Most of the periurethral injections were at the 3, 5, 7, and 9 o’clock positions and for submucosa were at the 4, 6, and 8 o’clock positions. No significant postoperative complications were reported.

Conclusion

Despite many challenges in stem cell-based therapy for treating SUI, it appears to provide, in both male and female patients, acceptable functional results with minimal side-effects and complications. In the future, more clinical trials should be funded in order to optimise stem cell-based therapy and evaluate long-term outcomes.

Abbreviations

ADSC: adipose-derived stem cell; BMSCs: bone marrow-derived mesenchymal stem cell; CLPP: cough leak-point pressure; FPL: functional profile length; HUCB: human umbilical cord blood stem cell; ICIQ-(QOL)(SF)(UI): International Consultation on Incontinence Questionnaire (Quality of life) (-Urinary incontinence Short Form) (-Urinary Incontinence); IIQ-7: Incontinence Impact Questionnaire-short form; I-QOL: Incontinence quality of life questionnaire; ISD: intrinsic urinary sphincter deficiency; MDSC: muscle-derived stem cell; MUCP: maximum urethral closure pressure; NR: not reported; Pdet-max: maximum detrusor pressure; PVR: post-void residual urine volume; Q_max: maximum urinary flow; QOL: quality of life; RP: radical prostatectomy; TNC: total nucleated cell; (S)UI: (stress) urinary incontinence; UDSCs: urine-derived stem cells; UTUS: upper tract ultrasonography; VLPP: Valsalva leak-point pressure

Stress urinary incontinence in women: Current and emerging therapeutic options

Surgical management of stress urinary incontinence (SUI) is most commonly achieved by midurethral synthetic sling (MUS) insertion as a first-line surgical option. A great deal of research continues to evolve new management strategies to reach an optimal balance of high efficacy and minimal adverse events. This expert opinion review provides a brief and comprehensive discussion of recent advances and ongoing research in the management of SUI, with an emphasis on single-incision mini-slings, vaginal laser treatment, and cell-based therapy. It is based on data obtained from numerous published meta-analyses and original studies identified through literature search. Single-incision mini-slings appear equally effective initially compared with standard MUS (retropubic or transobturator) for the treatment of female SUI; however, this efficacy lacks durability evidence beyond one-year followup. There is a lack of sufficient clinical evidence to currently confirm long-term safety and effectiveness of cell-therapy and non-ablative vaginal laser therapy, besides suggestion of apparent initial safety. There are still significant challenges to overcome before widespread clinical practice of the latter two modalities. Future research should be aimed at identifying groups of patients who might benefit from these minimally invasive therapeutic options.

The potential role of stem cells in the treatment of urinary incontinence

Voiding dysfunction encompasses a wide range of urologic disorders including stress urinary incontinence and overactive bladder that have a detrimental impact on the quality of life of millions of men and women worldwide. In recent years, we have greatly expanded our understanding of the pathophysiology of these clinical conditions. However, current gold standard therapies often provide symptomatic relief without targeting the underlying etiology of disease development. Recently, the use of stem cells to halt disease progression and reverse underlying pathology has emerged as a promising method to restore normal voiding function. Stem cells are classically thought to aid in tissue repair via their ability for multilineage differentiation and self-renewal. They may also exert a therapeutic effect via the secretion of bioactive factors that direct other stem and progenitor cells to the area of injury, and that also possess antiapoptotic, antiscarring, neovascularization, and immunomodulatory properties. Local injections of mesenchymal, muscle-derived, and adipose-derived stem cells have all yielded successful outcomes in animal models of mechanical, nerve, or external urethral sphincter injury in stress urinary incontinence. Similarly, direct injection of mesenchymal and adipose-derived stem cells into the bladder in animal models of bladder overactivity have demonstrated efficacy. Early clinical trials using stem cells for the treatment of stress urinary incontinence in both male and female patients have also achieved promising functional results with minimal adverse effects. Although many challenges remain to be addressed prior to the clinical implementation of this technology, novel stem-cell-based therapies are an exciting potential therapy for voiding dysfunction.

Neuromodulation of perineally transposed antropylorus with pudendal nerve anastomosis following total anorectal reconstruction in humans

BACKGROUND

We have reported perineal antropyloric segment transposition with its pudendal innervation as a replacement for anal sphincter. Our aim herein was to neuromodulate this segment by electrical stimulation.

METHODS

Eight patients with a permanent colostomy underwent perineal antropyloric segment transposition followed by neural anastomosis of its anterior vagus branch to pudendal nerve branch in the perineum. Perineal antropyloric graft was assessed for its functional integrity and electrophysiological effects. Nerve stimulation was done by surface stimulation technique, using a customized stimulation protocol for smooth muscle. Antral pressures were recorded on voluntary attempts and on nerve stimulation with simultaneous concentric needle electromyography of the perineal antropylorus.

KEY RESULTS

The antral segment showed slow spontaneous contractions (2-3/min) on digital examination, endoscopy, and electrophysiology. Stimulated antropyloric electromyography showed a latency of 2-5 s with a differential rise in amplitude (mean range 58.57-998.75 μV) according to the frequency of stimulation (range 10-150 Hz). An average latency of 10 s in relation to rise in the antral pressure was observed on pudendal nerve stimulation. Triggering of the intrinsic rhythm was observed in patients where it was initially absent. Voluntary attempts at contraction also showed a rise in perineally transposed antral pressure.

CONCLUSIONS & INFERENCES

Spontaneous rhythm, its generation after electrical stimulation, and response to voluntary contraction demonstrates the viability and functional reinnervation of the perineally transposed antropyloric segment. Rise in pressure on electrical stimulation shows evidence for its neuromodulation.

Functional outcome after anal sphincter injury and treatment with mesenchymal stem cells

This research demonstrates the regenerative effects of mesenchymal stem cells (MSCs) on the injured anal sphincter by comparing anal sphincter pressures following intramuscular and serial intravascular MSC infusion in a rat model of anal sphincter injury. Fifty rats were divided into injury (n = 35) and no injury (NI; n = 15) groups. Each group was further divided into i.m., serial i.v., or no-treatment (n = 5) groups and followed for 5 weeks. The injury consisted of an excision of 25% of the anal sphincter complex. Twenty-four hours after injury, 5 × 10(5) green fluorescent protein-labeled MSCs in 0.2 ml of phosphate-buffered saline (PBS) or PBS alone (sham) were injected into the anal sphincter for i.m. treatment; i.v. and sham i.v. treatments were delivered daily for 6 consecutive days via the tail vein. Anal pressures were recorded before injury and 10 days and 5 weeks after treatment. Ten days after i.m. MSC treatment, resting and peak pressures were significantly increased compared with those in sham i.m. treatment (p < .001). When compared with the NI group, the injury groups had anal pressures that were not significantly different 5 weeks after i.m./i.v. treatment. Both resting and peak pressures were also significantly increased after i.m./i.v. MSC treatment compared with treatment with PBS (p < .001), suggesting recovery. Statistical analysis was done using paired t test with Bonferroni correction. Marked decrease in fibrosis and scar tissue was seen in both MSC-treated groups. Both i.m. and i.v. MSC treatment after injury caused an increase in anal pressures sustained at 5 weeks, although fewer cells were injected i.m. The MSC-treated groups showed less scarring than the PBS-treated groups, with the i.v. infusion group showing the least scarring.

Stem cell therapy for stress urinary incontinence: a critical review

Stress urinary incontinence (SUI) is a prevailing health problem that severely impacts quality of life. Because SUI is mainly due to urethral sphincter deficiency, several preclinical and clinical trials have investigated whether transplantation of patient's own skeletal muscle-derived cells (SkMDCs) can restore the sphincter musculature. The specific cell type of SkMDCs has been described as myoblasts, satellite cells, muscle progenitor cells, or muscle-derived stem cells, and thus may vary from study to study. In more recent years, other stem cell (SC) types have also been tested, including those from the bone marrow, umbilical cord blood, and adipose tissue. These studies were mostly preclinical and utilized rat SUI models that were established predominantly by pudendal or sciatic nerve injury. Less frequently used animal models were sphincter injury and vaginal distension. While transurethral injection of SCs was employed almost exclusively in clinical trials, periurethral injection was used in all preclinical trials. Intravenous injection was also used in one preclinical study. Functional assessment of therapeutic efficacy in preclinical studies has relied almost exclusively on leak point pressure measurement. Histological assessment examined the sphincter muscle content, existence of transplanted SCs, and possible differentiation of these SCs. While all of these studies reported favorable functional and histological outcomes, there are questions about the validity of the animal model and claims of multilineage differentiation. In any event, SC transplantation appears to be a promising treatment for SUI.

Transplantation of mature adipocyte-derived dedifferentiated fat (DFAT) cells improves urethral sphincter contractility in a rat model

OBJECTIVES

To examine the effects of mature adipocyte-derived dedifferentiated fat (DFAT) cell transplantation on urethral tissue regeneration and sphincter function.

METHODS

Sixteen female Sprague-Dawley rats underwent vaginal distension (VD) for 3 h. Subsequently, green fluorescence protein (GFP)-labeled DFAT cells (1×10(6) in 20 µL saline, DFAT group, n=8) or saline (20 µL, control group, n=8) were injected into paraurethral connective tissue. Two weeks following VD, leak point pressure (LPP) was measured and an immunohistochemical analysis of the urethra was performed to evaluate urethral sphincter regeneration.

RESULTS

The VD model was characterized by atrophy of the urethral sphincter and showed a decrease in LPP. DFAT cell transplantation resulted in a significant improvement of LPP (DFAT group: 37.3±6.4 vs control group: 21.7±5.7 mmHg, P<0.01). Immunohistochemistry revealed that the striated muscle thickness and smooth muscle α-actin-positive area were significantly (P<0.05) larger in the DFAT group than in the control group. DFAT cell transplantation enhanced macrophage accumulation followed by an increased number of cells in the proliferative state. Transplanted DFAT cells were observed in the damaged smooth muscle layer and showed positive staining for smooth muscle α-actin, suggesting conversion into the smooth muscle cell phenotype.

CONCLUSIONS

DFAT cell transplantation promotes sphincter muscle regeneration and improves LPP in the rat VD model.

Regenerative medicine in urology

The term 'regenerative medicine' encompasses strategies for restoring or renewing tissue or organ function by: (i) in vivo tissue repair by in-growth of host cells into an acellular natural or synthetic biomaterial, (ii) implantation of tissue 'engineered'in vitro by seeding cultured cells into a biomaterial scaffold, and (iii) therapeutic cloning and stem cell-based tissue regeneration. In this article, we review recent developments underpinning the emerging science of regenerative medicine and critically assess where successful implementation of novel regenerative medicine approaches into urology practice might genuinely transform the quality of life of affected individuals. We advocate the need for an evidence-based approach supported by strong science and clinical objectivity.

Long-term cryopreservation of pyramidalis muscle specimens as a source of striated muscle stem cells for treatment of post-prostatectomy stress urinary incontinence

BACKGROUND

Stem-cell injection into the degenerated external urethral sphincter is a new treatment modality for stress urinary incontinence (SUI). We examined the possibility of long-term cryopreserved pyramidalis muscle (PM) specimens as a source of striated muscle stem cells for the treatment of post-prostatectomy SUI.

METHODS

PM specimens were obtained from five male patients (mean age, 61-70 years) who underwent radical prostatectomy for prostate cancer. Specimens (volume, approximately 125 mm³ ) were obtained from the incisional edge, minced, and stored at -80°C in a freezing medium (Cell Banker 1®). After 24-60 months, the specimens were thawed and directly incubated at 37°C. Satellite cells were selectively cultured by magnetic affinity cell sorting using an anti-neural cell adhesion molecule (NCAM) antibody. Osteogenic and adipogenic differentiation were induced by bone morphogenic protein-7 (BMP-7) and γ-linolenic acid, respectively.

RESULTS

NCAM-positive cells (>99% purity) were selectively cultured from all cryopreserved PM specimens and confirmed as being of striated muscle origin by the expression of desmin and MyoD. They fused and differentiated into multinucleated myotubes 7 days after incubation in a differentiation induction medium. Stimulation by BMP-7 and γ-linolenic acid induced expression of alkaline phosphatase (osteoblast marker) and lipid deposition within the cytoplasm (adipocyte characteristic), respectively.

CONCLUSIONS

Long-term cryopreserved PM specimens can be used to culture muscle stem cells. Therefore, this method may be utilized for SUI treatment when necessary. Moreover, complete remove of the prostate gland without fear of injury to the urethral sphincter may be possible in patients with apical cancer or T3 prostate cancer.

Transplantation of muscle-derived stem cells plus biodegradable fibrin glue restores the urethral sphincter in a pudendal nerve-transected rat model

We investigated whether fibrin glue (FG) could promote urethral sphincter restoration in muscle-derived stem cell (MDSC)-based injection therapies in a pudendal nerve-transected (PNT) rat, which was used as a stress urinary incontinence (SUI) model. MDSCs were purified from the gastrocnemius muscles of 4-week-old inbred female SPF Wistar rats and labeled with green fluorescent protein. Animals were divided into five groups (N = 15): sham (S), PNT (D), PNT+FG injection (F), PNT+MDSC injection (M), and PNT+MDSC+FG injection (FM). Each group was subdivided into 1- and 4-week groups. One and 4 weeks after injection into the proximal urethra, leak point pressure (LPP) was measured to assess urethral resistance function. Histology and immunohistochemistry were performed 4 weeks after injection. LPP was increased significantly in FM and M animals after implantation compared to group D (P < 0.01), but was not different from group S. LPP was slightly higher in the FM group than in the M group but there was no significant difference between them at different times. Histological and immunohistochemical examination demonstrated increased numbers of surviving MDSCs (109 ± 19 vs 82 ± 11/hpf, P = 0.026), increased muscle/collagen ratio (0.40 ± 0.02 vs 0.34 ± 0.02, P = 0.044), as well as increased microvessel density (16.9 ± 0.6 vs 14.1 ± 0.4/hpf, P = 0.001) at the injection sites in FM compared to M animals. Fibrin glue may potentially improve the action of transplanted MDSCs to restore the histology and function of the urethral sphincter in a SUI rat model. Injection of MDSCs with fibrin glue may provide a novel cellular therapy method for SUI.

Endoscopic injection of skeletal muscle-derived cells augments gut smooth muscle sphincter function: implications for a novel therapeutic approach

INTRODUCTION

Sphincter function is a common problem in gastroenterology and leads to disorders such as GERD and fecal incontinence.

OBJECTIVE

We hypothesized that transplantation of skeletal muscle-derived cells (MDCs) into GI sphincters may improve their function, leading to a more physiological approach to treating these disorders.

DESIGN

We performed experiments to test the potential of MDCs to survive and differentiate within the GI smooth muscle in order to gain further knowledge on the biology of skeletal muscle transplantation in GI smooth muscle sphincters as well as to test the safety and feasibility of endoscopic injection of MDCs in a large animal model.

SETTING

Animal laboratory.

INTERVENTIONS

Adult male Sprague-Dawley rats and adult male beagle dogs were used. Rat-derived and dog-derived MDCs were prepared in vitro and labeled with DiI. DiI-labeled, rat-derived MDCs (200,000/4 muL phosphate buffered saline solution) were injected bilaterally in the pyloric wall of rats, and survival, differentiation, and in vitro contractility were assessed 1 month after transplantation. Dog-derived MDCs (4.0 x 10(6) cells) were also injected into the lower esophageal sphincter of 3 beagle dogs by using a standard variceal sclerotherapy needle after baseline esophageal manometry and pH monitoring. The dogs were treated with daily cyclosporine, and 2 weeks later esophageal manometry was repeated and the esophagus was examined histologically. Differentiation of grafted cells was assessed by immunofluorescence, using specific antibodies to markers of the smooth muscle phenotype (smooth muscle actin) and of the skeletal muscle phenotype (skeletal muscle myosin).

RESULTS

In rats, grafted MDCs were visualized based on DiI fluorescence and were found to be localized within the muscle wall and in the muscularis mucosa. In vitro organ bath studies showed a significant increase in the contractile response of the pyloric sphincter to exogenous acetylcholine. In dogs, MDC injection resulted in a significant increase in baseline lower esophageal sphincter pressure. Further, in 1 dog with significant baseline acid reflux, MDC injection resulted in a reduction of acid reflux, with the fraction of time with pH <4 decreasing from 26.5% to 1.5%. Transplanted MDCs were seen adding bulk to the lower esophageal area and were well-integrated into the surrounding tissue. Immunofluorescence analysis revealed weak expression of skeletal muscle myosin in grafted MDCs and no expression of smooth muscle actin in either rats or dogs.

LIMITATIONS

Animal study.

CONCLUSION

MDCs can survive and integrate into GI smooth muscle and augment their contractile response. Thus, they may have potential for the treatment of a variety of conditions.

Vibratory perception and female stress urinary incontinence

PURPOSE

We investigated the value of measuring the vibratory perception threshold with a biothesiometer to clinically evaluate women with stress urinary incontinence.

MATERIALS AND METHODS

The study consisted of 3 groups, including group 1--66 women with stress urinary incontinence, group 2--44 age matched women without stress urinary incontinence and group 3--60 younger women without stress urinary incontinence. A total of 50 patients with stress urinary incontinence underwent videourodynamics. Using a biothesiometer the vibratory perception threshold was measured over the middle finger, middle toe and clitoris in all study subjects. A higher threshold indicated lower sensitivity to vibratory stimulation. Motions leading to stress urinary incontinence were also determined.

RESULTS

The stress urinary incontinence and age matched control groups were older than the younger control group and had greater parity. The incontinence group had a higher vibratory perception threshold than the younger control group but there was no difference between women with incontinence and age matched women without incontinence. Women in whom incontinence was induced by walking upstairs or downstairs had a higher finger and toe vibratory perception threshold than those without incontinence. The threshold in the groups with and without intrinsic sphincter deficiency did not differ significantly.

CONCLUSIONS

Vibratory perception is not related to stress urinary incontinence in females. Finger and toe vibratory perception is less sensitive in patients with stress urinary incontinence while walking upstairs or downstairs.

Muscle derived stem cell therapy for stress urinary incontinence

AIM

The aim of this article is to discuss the potential of muscle-derived stem cells (MDSCs) for rhabdosphincter regeneration and to review the early clinical experiences with its application in patients with stress urinary incontinence.

RESULTS

In anatomical and functional studies of the human and animal urethra, the middle urethral contained rhabdosphincter is critical for maintaining continence. Transplanted stem cells have the ability to undergo self-renewal and multipotent differentiation, leading to sphincter regeneration. In addition, such cells may release, or be engineered to release, neurotrophins with subsequent paracrine recruitment of endogenous host cells to concomitantly promote a regenerative response of nerve-integrated muscle.

CONCLUSION

Cell-based therapies are most often associated with the use of autologous multipotent stem cells, such as bone marrow stromal cells. However, harvesting bone marrow stromal stem cells requires a general anesthetic, can be painful, and has variable yield of stem cells upon processing. In contrast, with appropriate experience, alternative autologous adult stem cells such as muscle-derived stem cells and adipose-derived stem cells can be obtained in large quantities and with minimal discomfort.

Physiological effects of human muscle-derived stem cell implantation on urethral smooth muscle function

The physiological effects of human muscle-derived stem cell (MDSC) implantation on urethral smooth muscle function were investigated in pudendal nerve-transected nude rats with human MDSC (TM) or saline (TS) injection into the proximal urethra compared with sham-operated, saline-injected nude rats (SS). Leak point pressure (LPP) before and after hexamethonium application, which can block autonomic efferent nerves, and proximal urethral contractile responses to carbachol and phenylephrine in muscle strip study were examined 6 weeks after the implantation. There was no significant difference between the LPPs in SS and TM. Following hexamethonium application, the LPP in TM was, however, significantly decreased compared with SS. The contractile responses to phenylephrine, but not to carbachol, in TM were significantly increased compared with SS and TS. These results suggest that the restorative effects of MDSCs are mediated by autonomic nerves and that increased sensitivity of alpha(1)-adrenoceptors may be related to restore the deficient urethral function.