NEUROUROLOGY & FEMALE UROLOGY

State of the art of where we are at using stem cells for stress urinary incontinence
Furuta A, Jankowski RJ, Honda M, Pruchnic R, Yoshimura N, Chancellor MB
Department of Urology, University of Pittsburgh School of Medicine, Pennsylvania, USA
Neurourol Urodyn. 2007; 26: 966-71

• Aims: This review aims to discuss: 1) the neurophysiology, highlighting the importance of the middle urethra, and treatment of stress urinary incontinence (SUI); 2) current injectable cell sources for minimally-invasive treatment; and 3) the potential of muscle-derived stem cells (MDSCs) for the delivery of neurotrophic factors.
• Methods: A PUB-MED search was conducted using combinations of heading terms: urinary incontinence, urethral sphincter, stem cells, muscle, adipose, neurotrophins. In addition, we will update the recent work from our laboratory.
• Results: In anatomical and functional studies of human and animal urethra, the middle urethra containing rhabdosphincter, is critical for maintaining continence. Cell-based therapies are most often associated with the use of autologous multipotent stem cells, such as the bone marrow stromal cells. However, harvesting bone marrow stromal stem cells is difficult, painful, and may yield low numbers of stem cells upon processing. In contrast, alternative autologous adult stem cells such as MDSCs and adipose-derived stem cells can be easily obtained in large quantities and with minimal discomfort. Not all cellular therapies are the same, as demonstrated by the differences in safety and efficacy from muscle-sourced MDSCs versus myoblasts versus fibroblasts.
• Conclusions: Transplanted stem cells may 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. The dawn of a new paradigm in the treatment of SUI may be near.
  
  
• Editorial Comment
  The authors describe the current status of research into using stem cell therapy for stress urinary incontinence. This is an excellent read for those who wish to gaze through the looking glass into the future of urology. The last paragraph of the Introduction section alone is worth reading and looking back upon in one or two decades to see if the predictions are fulfilled. Clearly, patient interest will continue to drive us away from surgery and into minimally invasive therapies to restore functionality to diseased areas of the urologic system. One does not have to wait a decade to already notice this desire (1). The section on neurophysiology is clear and distinct as is the discussion on stem cell therapy and the reasoning of using muscle-derived stem cells.

Reference
1. Petrou SP, Lisson SW, Crook JE, Lightner DJ: An exploration into patient preference for injectable therapy over surgery in the treatment of female urinary incontinence. Int Braz J Urol. 2006; 32: 578-82.

Dr. Steven P. Petrou
Associate Professor of Urology
Chief of Surgery, St. Luke’s Hospital
Associate Dean, Mayo School of Graduate Medical Education
Jacksonville, Florida, USA
E-mail: petrou.steven@mayo.edu