title: Cochlear implantation in children: labyrinthitis following pneumococcal otitis media in unimplanted and implanted cat cochleas.
abstract: Pneumococcal otitis media is frequent in young children and could lead to labyrinthitis post-implantation. To assess the risk, and methods of minimizing it by a graft to the round window around the electrode entry point, we have used a cat animal model of pneumococcal otitis media. Twenty-one kittens were used in the study. Thirty-two cochleas were implanted when the kittens were 2 months of age. Fourteen cochleas were implanted without using a graft (12 were available for study); 9 had a fascial graft, and 9 a Gelfoam graft (7 were available for study). The implanted kittens had their bullae inoculated with Streptococcus pneumoniae 2 months after implantation and were sacrificed 1 week later. There were also 9 unimplanted control ears which were inoculated when the animals were 4 months of age. Labyrinthitis occurred in 44% of unimplanted control, 50% of implanted ungrafted, and 6% of implanted grafted (fascia and Gelfoam) cochleas. There was no statistically significant difference between the unimplanted control and the implanted cochleas (p < 0.05). There was, however, a difference between the implanted-ungrafted and implanted grafted cochleas, but not between the use of fascia and Gelfoam to graft the round window entry point. As a result, the data indicates that cochlear implantation does not increase the risk of labyrinthitis following pneumococcal otitis media, but it is desirable to use fascia as a graft to the round window around the electrode entry point.
authors.affiliation: Department of Otolaryngology, University of Melbourne, Australia.
authors.forename: M C
authors.initials: MC
authors.lastname: Dahm
authors.forename: G M
authors.initials: GM
authors.lastname: Clark
authors.forename: B K
authors.initials: BK
authors.lastname: Franz
authors.forename: R K
authors.initials: RK
authors.lastname: Shepherd
authors.forename: M J
authors.initials: MJ
authors.lastname: Burton
authors.forename: R
authors.initials: R
authors.lastname: Robins-Browne
mesh_terms: D000818:Animals; D002415:Cats; D003051:Cochlea / Q000503:physiopathology / Q000601:surgery* / Q000648:ultrastructure; D003054:Cochlear Implants; D003638:Deafness / Q000534:rehabilitation; D007758:Ear, Inner / Q000503:physiopathology / Q000601:surgery*; D004432:Ear, Middle / Q000382:microbiology*; D007762:Labyrinthitis / Q000209:etiology* / Q000503:physiopathology; D010033:Otitis Media / Q000150:complications / Q000382:microbiology*; D012405:Round Window, Ear / Q000503:physiopathology / Q000601:surgery; D013296:Streptococcus pneumoniae / Q000302:isolation & purification*