Urethral bulking with polymethylmethacrylate microspheres for stress urinary incontinence: tissue persistence and safety studies in miniswine.

Autor: Lemperle G; Surgical Animal Laboratory, University of California, San Diego, CA 92037, USA. glemperle@aol.com, Lappin PB, Stone C, Lemperle SM
Jazyk: angličtina
Zdroj: Urology [Urology] 2011 Apr; Vol. 77 (4), pp. 1005.e1-7. Date of Electronic Publication: 2011 Feb 18.
DOI: 10.1016/j.urology.2010.12.021
Abstrakt: Objectives: To evaluate the safety and persistence of injectable polymethylmethacrylate (PMMA) microspheres as a long-lasting urethral bulking agent in pigs. PMMA microspheres of 2 different diameters (40 and 125 μm) were tested to investigate the potential for migration and dislocation after injection. A similar product containing 40-μm PMMA microspheres has been used as an injectable wrinkle filler for >25 years and received Food and Drug Administration approval in 2006 (ArteFill).
Methods: A total of 22 female pigs received 4 submucosal implantations of PMMA microspheres, using either a cystoscope or a newly developed urethral injection device (UroScope). At death and necropsy at 8 days and 1, 3, and 6 months, the urethral injection site, liver, lung, spleen, and pelvic and iliac lymph nodes were processed for histologic examination and microsphere count using organ dissolution and microscopy.
Results: All injected submucosal blebs were still present at 6 months and showed no signs of inflammation. Tissue dissolution of the local lymph nodes and major organs demonstrated the transport of some of the 40-μm microspheres to the local lymph nodes and lung but not to the liver or spleen. In contrast, no 125-μm microspheres were detected in any distant organ.
Conclusions: The submucosal implantation of 125-μm PMMA microspheres into the urethra provided a safe and persistent bulking effect in pigs. The positive results of the present study encourage additional investigation of 125-μm PMMA microspheres as a long-lasting bulking agent for the treatment of female stress urinary incontinence. Furthermore, a newly developed urethral injection device (UroScope) proved beneficial and cost-effective to facilitate the transurethral injections of 125-μm PMMA microspheres.
(Copyright © 2011 Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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