June 28, 2007 -- Injections of stem cells and other cells obtained from a woman's own body can treat stress urinary incontinence with dramatically better results than conventional collagen injections, according to a new study from Austria.
The results, which mimic those from similar research under way in the U.S., might also be long-lasting. "The treatment might have a chance to be permanent," Giacomo Novara, MD, a doctor at the University of Padua in Italy, tells WebMD in an email interview. Novara wrote a comment accompanying the study. Both appear in the June 30 issue of The Lancet.
More than 13 million women in the U.S. suffer from stress urinary incontinence, a condition much more common in women than in men. The condition develops as the urethral sphincter muscles, which control the flow of urine, weaken, typically after childbirth or with age. When a person coughs, sneezes, or laughs, urine can leak.
The Austrian Study
The Austrian researchers, led by Hannes Strasser, MD, from the Medical University of Innsbruck, compared the effects of the stem cell injections with conventional injections of collagen in 63 women with stress urinary incontinence.
They first performed a small muscle biopsy on the upper arms of the 42 women assigned to get the stem cell injections. In the laboratory, they retrieved myoblasts, a type of muscle stem cell, and fibroblasts, cells which form the structural framework for many body tissues. Both types of cells have been shown effective in reconstructing the lower urinary tract in animal studies, according to Strasser.
Next, guided by ultrasound, Strasser's team injected the cells back into the women's sphincter and surrounding area.
Traditional collagen injections, which don't typically have a high success rate for incontinence, were given to the other 21 women. Collagen treatments work by bulking up the area to compress the urethra -- helping to hold urine.
After 12 months, 38 of the 42 women given the stem cell and other cell injections were completely continent. The other four showed either slight or substantial improvement. But just two of the 21 who got collagen injections were continent; seven others showed either slight or substantial improvement.
On ultrasound exams after the injections, the thickness of the sphincter had increased 59% in the women given cell injections but just 9% in the collagen-treated group. The muscle contractibility rose much more in the cell group. Increases in the sphincter thickness and muscle contractibility are thought to help improve symptoms.
Women treated with the injections of cells reported higher quality of life than the collagen-treated group.
None of the women reported any adverse side effects.
Strasser is a founder and co-owner of the biotechnology company at which the retrieved cells were prepared, but the company had no role in the research, he says.
The Austrian study shows "promising results," according to Michael Chancellor, MD, a professor of urology and director of the neurourology and urinary incontinence programs at the University of Pittsburgh.
He has been conducting similar research and presented his findings in May 2007 at the annual meeting of the American Urological Association in Anaheim, Calif.
In that study, Chancellor and his colleagues injected adult stem cells derived from the person's own muscle into the weakened sphincter and found after a year and half that five of the eight women with urinary incontinence studied got modest improvement; one woman was completely continent. The study was a safety study, considered preliminary, and done in cooperation with the University of Toronto and Health Canada.
In his editorial, Novara calls the study results "impressive" and writes: "If the data are confirmed, this approach is likely to cause a substantial change in the treatment of female urinary incontinence."
If the research bears out, the new approach "may indeed be a true breakthrough in the management of incontinence," says Roger R. Dmochowski, MD, a spokesman for the American Urological Association and director of the Vanderbilt University Continence Center in Nashville, Tenn. "This study has surprisingly good data and actually shows not only durability of the injected tissue but also functionality of that tissue, which is impressive at this time." But he says more follow-up is needed and other researchers need to reproduce the results.
Perspective on Urinary Incontinence
Urologists agree that better options are sorely needed for stress incontinence. Currently, doctors treating women with the condition suggest pelvic floor exercise or Kegels to strengthen the pelvic floor muscles, biofeedback to retrain the muscles, or a variety of surgical options. One procedure involves inserting a mesh-like tape that serves as a kind of sling to support the urethra and prevent the involuntary leakage of urine.
Timeline for Stem Cells for Urinary Incontinence
Similar research on injecting a person's own cells for incontinence treatment is ongoing not only in the U.S. and Austria but also in several European centers, according to Novara.
If additional research proceeds on schedule, the cell injection treatment could be available in the U.S. in less than three years, Chancellor estimates.
Dmochowski is less optimistic about the timelines. Look for the new treatment to be available, he says, "not earlier than three to five years from now and possibly as long as seven to 10."