Stem cells, botulinum lead advances in incontinence

May 15, 2005

The use of non-embryonic stem cells and the growing popularity of botulinum toxin are among key trends to watch for in the management of stress incontinence and overactive bladder, respectively, said Shlomo Raz, MD, director of female urology, urodynamics, and reconstructive surgery at UCLA Medical Center.

One of the more novel and exciting developments in the management of stress incontinence is the use of stem cells. These may someday become a substitute for surgical reconstruction, Dr. Raz predicted. These cells are not embryonic stem cells but are derived from a variety of tissues such as adipose (fat) tissue. Larissa Rodriguez, MD, at UCLA, and Michael Chancellor, MD, at the University of Pittsburgh, have both achieved singular success in animal experiments.

Researchers at the Medical University of Innsbruck, Austria, have initiated clinical trials using stem cells derived from muscle tissue. The cells are grown for 6 weeks in a culture and injected into bladder muscles and the urethra in a 20-minute outpatient procedure. Of the first 20 women receiving the treatment, 18 reported having no incontinence at the end of 1 year.

"All these studies are very promising. The cells are staying in place and appear to be regenerating the urethra. Perhaps someday no surgery will be required to treat many types of incontinence. We will be able to regenerate deficient tissue. But there remain a number of unanswered questions," said Dr. Raz.

Botulinum on the rise In the area of overactive bladder, botulinum toxin (Botox) as a means of managing refractory urge incontinence is seeing increased use, Dr. Raz pointed out, even though the agent has yet to be approved for this indication. He also observed that the profession is enjoying a wealth of new drugs that target bladder receptors more specifically.

Three new anticholinergic agents were approved last year, and more are in the pipeline. Solifenacin succinate (Vesicare) relieves urge incontinence by blocking muscarinic acetylcholine receptors on the bladder. Trospium chloride (Sanctura) is a compound that targets muscarinic receptors and relaxes smooth muscle tissue in the bladder. Darifenacin (Enablex) is a highly selective re-ceptor antagonist that binds to the M3 receptor to inhibit the detrusor muscle. The trend to develop agents specific to bladder receptors is will continue, said Dr. Raz.

Among other advances: