URINARY INCONTINENCE

In addition, immunohistochemistry and histology showed persistence of the human muscle-derived stem cells in the injected rats, versus periurethral muscle atrophy in the rats that had nerve transection but no injection.

Clinical testing underway

Clinical trials of this technology in women are now being performed in Toronto. It will be necessary to show safety and efficacy before the stem cell therapy is made available clinically, but there are a couple of factors in its favor:

• In terms of safety, the risks associated with the current crop of injectable materials should not be applicable, at least in theory. Because the injected stem cells are isolated and grown from the patient’s own biopsy, the chance of an adverse immunologic reaction should be zero, absent the rare mistake in labeling or transfer.
• The cell-injection technique is well-established and already used by many clinicians who perform transurethral or periurethral injection of bulking agents for women with incontinence. It will not be necessary to learn a new technique—just injectable material.

Tissue-engineered sling also in the works

Given that incontinence (and, presumably, the level of urethral damage resulting in some women may have urethral damage so severe as to preclude benefit from the injection of relatively small numbers of researchers is already developing a tissue-engineered sling in the hope that it can be used as a substitute for currently available synthetic or biologic sling materials.

The sling is being developed with the same muscle-derived stem cells, which are seeded onto a scaffold for as little as 2 weeks in a rat model. After the sling was surgically implanted using standard technique, urethral function improved to the level seen among controls.

It may be that the promise of stem cell therapy will come early to the treatment of urinary incontinence. Time will tell.

The author reports no financial relationships relevant to this article.