title: Particulate silicone for use in periurethral injections: local tissue effects and search for migration.
abstract: We examined the histologic behavior and migratory tendencies of a silicone-based injectable paste (Macroplastique) with potential application in treating urinary incontinence. Thirteen female dogs were studied. Six received 2 periurethral injections of large-particle paste, with a median diameter of 110 microns, and 7 received similar injections with small-particle paste (median diameter, 73 microns). The paste was radiolabeled with cobalt-57. Histologic analysis was performed at 4 or 9 months. The pathologic appearance revealed intact large-particle injection sites. The small-particle sites had dissipated significantly. This was confirmed by nuclear imaging. Large particles produced an encapsulated fibrous sheath without local migration. There was a histiocytic reaction within the injection site but no granuloma formation. Distant migration was observed in 1 dog (short term, large particle), without an inflammatory response. Migration of silicone occurred locally and distantly in animals that received small particles. X-ray microanalysis confirmed the presence of silicone particles.
authors.affiliation: Department of Urology, Mayo Clinic, Rochester, Minnesota 55905, USA.
authors.forename: D R
authors.initials: DR
authors.lastname: Henly
authors.forename: D M
authors.initials: DM
authors.lastname: Barrett
authors.forename: T L
authors.initials: TL
authors.lastname: Weiland
authors.forename: M K
authors.initials: MK
authors.lastname: O'Connor
authors.forename: A A
authors.initials: AA
authors.lastname: Malizia
authors.forename: A J
authors.initials: AJ
authors.lastname: Wein
mesh_terms: D000818:Animals; D004285:Dogs; D005260:Female; D005548:Foreign-Body Migration / Q000209:etiology / Q000473:pathology*; D007267:Injections; D008854:Microscopy, Electron; D010316:Particle Size; D012828:Silicones / Q000008:administration & dosage* / Q000009:adverse effects; D014521:Urethra; D014549:Urinary Incontinence / Q000628:therapy*
chemical_list: D012828:Silicones