Bulking Agents - Do they work for Men with Stress Incontinence?

The "collagen" referred to in the article is just one many substances used for controlling stress incontinence. These substances are collectively referred to as "bulking agents." Among the many types are:

• Tegress (formerly call Uryx): This product was originally produced by Genyx Medical, which has since been purchased by C.R. Bard. Bard discontinued this product in December, 2007. (I list it here because it is found when searching for information on bulking agents on the Internet.)
• Durasphere: Comprised of carbon bead particles, this is produced by Carbon Medical Technologies.
• Contigen: C. R. Bard. This is bovine glutaraldehyde cross-linked collagen.
• Coaptite: Originally produced by Bioform Medical, it now markets Coaptite through Boston Scientific. This product is comprised of 100 micron spheres of calcium hydroxylapatite, a synthetic form of a natural material found in bones.
• PTFE (Teflon) Paste: Marketed at "Polytef", it is currently not available in the US. Was used early on until it was discovered that some of the particles may migrate to other areas of the body, with unknown consequences.

There are three techniques that are used:

• Transurethral: A rigid cystoscope is inserted into the urethra and position just below the bladder neck. A needle is pass through the scope and through the urethral wall. The bulking agent is injected just below the urethral mucosa. The scope is rotated a two or three more times and the process repeated.
• Periurethral: A rigid cystoscope is inserted into the urethra, but the bulking agent is injected from outside the urethral opening (meatus). There is small cleft between the meatus and the surrounding tissue above the vagina. A needle is inserted into this cleft and positioned using the view from the cystoscope as a guide for placement. Once the tip of needle is in satisfactory position, the bulking agent is inject. This process is repeated two or three more times around the periphery of the urethra. This procedure may require more anesthesia than transurethral, and is performed exclusively for women.
• Antegrade: This is usually reserved for men with severe post-prostatectomy incontinence. The bladder is opened suprapubically and the bulking agent is inject from inside the bladder, adjacent to the bladder neck. This procedure is considered surgery and must be performed in the operating room with appropriate anesthesia and pain control.

While the usual injection location is in the urethral mucosa of the bladder neck, some surgeons have had success injecting material below the bladder neck, sometimes as much as an inch or more.

Bulking agents last usually from six months to year, although some people have gone longer than that. The bulking agents described above have FDA approval for use in women only. There is quite a bit of data on the efficacy of bulking agents for females, but not much on how well it works for males.

Some studies indicate success rates for women of nearly 80%, depending on the bulking agent used. One study that compared Durasphere to collagen found an 80% success rate for Durasphere as compared to a 69% success rate for collagen. Other studies have found that collagen may be nearly as effective. Many of these bulking agents remain affective for at least 6 months, some for a year or more. However, clinical studies with male subjects do not achieve these rates.