Another year is drawing to a close and, looking back, what have we learned about urinary incontinence? A clear understanding of etiology stubbornly eludes us. How would a clear understanding of etiology affect management? It’s difficult to be specific until we actually do understand it, but generally:
The “multiple-hit” theory probably applies to urinary incontinence, too
The “multiple-hit” theory usually ascribed to cancer probably also fits the development of urinary incontinence, a likewise multifaceted condition. A woman begins life with genetic predisposition at some level that we cannot currently measure, but which is influenced by the environment (eg, nutrition, toxic exposures) and life events (eg, childbirth, aging)—all of which determine her likelihood of developing incontinence.
Until the time when we do have a clear understanding on which to base diagnosis, treatment, and prevention, of course, we must continue to manage incontinence with the tools of today.
A few pieces of the puzzle are slowly coming together.
Even as new surgical techniques or modifications continue to proliferate, evidence to guide clinical practice accumulates belatedly. MEDLINE lists 325 articles since 1996 (combining surgical mesh and urinary incontinence, limited to human females and published in English). Nonetheless, a consensus may be emerging that the safest synthetic material is monofilament polypropylene with pore size larger than 70 μm.
Unfortunately, by the time research reports are published showing higher complications with certain products, countless women have already been treated.
Mesh erosion (or exposure, extrusion), sometimes accompanied by infection, is a common complication when multifilament or small-pore meshes are used. Even worse, companies commonly withdraw products, modify them, and re-introduce them to the market, accompanied by intensive marketing but, as with the original product, without any real evidence of safety and effectiveness.
In an ideal world, clinicians (and patients) would insist on evidence before accepting new products and techniques. Failing that, clinicians (and patients!) should clearly understand that all new products and techniques are experimental until they are proven equal to or better than traditional techniques. As we have learned with the most subtle differences between synthetic materials, “almost the same” or “looks the same” is not the same.
Among the most important evidence on slings this year are reports of investigations that demonstrated what should not be done.
Are monofilament, large-pore mesh products safer?
Abdel-Fattah M, Sivanesan K, Ramsay I, Pringle S, Bjornsson S. How common are tape erosions? A comparison of two versions of the transobturator tension-free vaginal tape procedure. BJU Int. 2006;98:594–598.
Yamada BS, Govier FE, Stefanovic KB, Kobashi KC. High rate of vaginal erosions associated with the Mentor Obtape. J Urol. 2006;176:651–654.
Siegel AL, Kim M, Goldstein M, Levey S, Ilbeigi P. High incidence of vaginal mesh extrusion using the Intravaginal Slingplasty sling. J Urol. 2005;174:1308–1311.
The risk of vaginal erosion is much higher with synthetic meshes used for sling procedures when the mesh is multifilament and/or small-pore (<70 μm). In some cases, companies have replaced products (Mentor Obtape small-pore polypropylene sling product was replaced with macroporous Aris), whereas others continue to market products reported to have unacceptably high rates of vaginal erosion and mesh extrusion (Intravaginal Slingplasty multifilament mesh) (TABLE 1).
Comparison of selected multifilament and small-pore mesh products
|REFERENCE||SLING PRODUCT||EROSION RATE||MANAGEMENT|
|Abdel-Fattah et al (2006)||Obtape||7.3% (14 of 192)||7: partial excision |
7: complete excision with infection
|TVT-O||1.8% (2 of 112)||1: partial excision |
1: vaginal closure
|Yamada et al (2006)||Obtape||13.4% (9 of 67)||9: complete excision (1 with abscess)|
|Monarc||0 of 56||—|
|Siegel et al (2005)||IVS||17% (6 of 35)||6: complete excision (1 with pelvic abscess)|
Avoid cadaveric fascia in sling procedures
Howden NS, Zyczynski HM, Moalli PA, Sagan ER, Meyn LA, Weber AM. Comparison of autologous rectus fascia and cadaveric fascia in pubovaginal sling continence outcomes. Am J Obstet Gynecol. 2006;194:1444–1449.
Evidence has accumulated that sling procedures performed with cadaveric fascia have substantially worse continence outcomes, compared with those using autologous fascia. In a retrospective cohort study of 150 women with cadaveric fascial slings and 153 women who had autologous rectus fascial slings, urinary incontinence (16 vs 5 per 100 women-years) and reoperation for stress incontinence (4 vs 1 per 100 women-years) occurred more frequently after cadaveric versus autologous rectus fascial slings.