By David S. MacDougall
CHICAGO—Ultrasound-guided injection of autologous stem cells into the urethral wall and sphincter may be an effective approach to the treatment of stress urinary incontinence, according to findings presented at the 2005 annual meeting of the Radiological Society of North America.
“Urinary incontinence can be treated very effectively with autologous stem cells,” said Ferdinand Frauscher, MD, of the Medical University of Innsbruck, Austria. “This therapeutic concept represents a revolutionary and very promising treatment modality.”
Normal aging is associated with increased urethral atrophy and significant decreases in the number of myocytes populating the rhabdosphincter. These changes correlate with the increasing incidence of urinary incontinence in older women, Dr Frauscher stated.
In a study conducted by Dr Frauscher and colleagues, 20 women with mild-to-severe stress incontinence received injections of autologous myoblasts and fibroblasts into urethral structures under 3-dimensional (3-D) ultrasound guidance. The cells were obtained from single skeletal muscle biopsies taken from the left arm and cultured using a technique that yielded about 50 million myoblasts and 50 million fibroblasts after 6 weeks.
These are very intelligent cells,” Dr Frauscher said. “They quickly form new muscle tissue and when the muscle mass reaches the appropriate size, cell growth ceases automatically.”
The fibroblasts were combined with collagen as a carrier and injected into the urethral submucosa to improve mucosal atrophy. Myoblasts were injected directly into the rhabdosphincter to increase muscle mass and contractility.
The development of transurethral 3-D ultrasound was a major factor in the success of the treatment. “With real-time ultrasound, we were able to see exactly where the new cells must be placed,” Dr Frauscher explained.
The majority of patients reported significant improvement in urinary continence on the day following stem cell injection. Urinary incontinence and quality-of-life scores increased significantly at 1 week after treatment.
At 1 year after treatment, 18 women (90%) remained completely continent. The 2 women in whom stem cell injection was unsuccessful were the oldest members of the study group.
Follow-up transurethral ultrasound examinations revealed significant increases in the thickness of the urethra and rhabdosphincter (P <.001 for both) at 1 year after treatment.. These changes were associated with maintenance of improvements in quality of life and increased rhabdosphincter contractility.
Ultrasound-guided injection of stem cells was performed on an outpatient basis without any significant complications or adverse effects. No postprocedure infections or other complications were observed.
Dr Frauscher noted that the cost of the stem cell procedure is comparable with that of urethral collagen injections, which have shown limited short-term efficacy, and the long-term use of adult diapers.