ANAHEIM, Calif.—Women with stress urinary incontinence (SUI) injected with muscle-derived stem cells to strengthen their sphincter muscles experience long-term improvement, according to a small study.
“This trial is encouraging, given that 13 million people in the United States, most of them women, cope with stress urinary incontinence,” said Michael Chancellor, MD, professor of urology and gynecology at the University of Pittsburgh School of Medicine. “We’re demonstrating that we may be able to offer people with SUI a long-term and minimally invasive treatment option.”
Dr. Chancellor and his colleagues at the University of Toronto previously have shown that injection of muscle-derived cells (MDC) into periurethral muscle resulted in increased leak point pressures (LPP) in an animal model of SUI. Dr. Chancellor presented the results of the first completed North American clinical trial using autologous MDC for SUI in women with one-year follow-up.
Eight women (aged 41-66 years) to date have been treated with either a transurethral or periurethral injection technique; three received a re-injection after six months. All the patients have completed one year of follow-up. No serious adverse events or safety issues have been identified so far, and five patients have demonstrated sustained improvements in pad weight tests. In addition, these five patients reported improvement in bladder control and quality of life with no serious short-term or long-term adverse effects.
With this approach, skeletal muscle tissue (42-247 mg) was harvested using a needle biopsy technique, placed in a hypothermic solution and then transported to a cell-processing center. The MDCs were isolated and expanded in culture (18-22 x 106 cells). About four weeks after biopsy, the women had an outpatient MDC injection with only local anesthesia.
Each patient received an equal dose of stem cells using three techniques: a transurethral injection with either an 8-mm or 10-mm needle or a periurethral injection. The patients kept a diary and were followed up at 1, 3, 6, and 12 months.
“The technique to achieve optimal efficacy is evolving,” said principal investigator Lesley Carr, MD, a urologist at Sunnybrook Health Sciences Centre and assistant professor of urology at the University of Toronto. “We now have preliminary evidence that stem cells are safe to use and appear to improve female stress urinary incontinence.”
The best results occurred in the patients with both the 10-mm needle injections and the periurethral injections, which allowed delivery of stem cells closer to the damaged sphincter muscle. The 8-mm needle was unable to deliver the stem cells deep enough into the tissue. A multicenter study is under way to determine the optimal stem cell dose.