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dc.contributor.authorShepherd, Robert K.en_US
dc.contributor.authorClark, Graeme M.en_US
dc.contributor.authorXu, Shi-Angen_US
dc.contributor.authorPyman, Brian C.en_US
dc.date.accessioned2014-05-21T20:24:03Z
dc.date.available2014-05-21T20:24:03Z
dc.date.issued1995en_US
dc.identifier.citationShepherd, R. K., Clark, G. M., Xu, S., & Pyman, B. C. (1995). Cochlear pathology following reimplantation of a multichannel scala tympani electrode array in the macaque. American Journal of Otology, March, 16(2), 186-199.en_US
dc.identifier.urihttp://hdl.handle.net/11343/27416
dc.descriptionThis is a publisher’s version of an article published in American Journal of Otology 1995. This version is reproduced with permission of Lippincott Wilkins & Williams.en_US
dc.description.abstractThe histopathologic consequence of removing and reimplanting intracochlear electrode arrays on residual auditory nerve fibers is an important issue when evaluating the safety of cochlear prostheses. The authors have examined this issue by implanting multichannel intracochlear electrodes in macaque monkeys. Macaques were selected because of the similarity of the surgical technique used to insert electrodes into the cochlea compared to that in humans, in particular the ability to insert the arrays into the upper basal turn. Five macaques were bilaterally implanted with the Melbourne/Cochlear banded electrode array. Following a minimum implant period of 5 months, the electrode array on one side of each animal was removed and another immediately implanted. The animals were sacrificed a minimum of 5 months following the reinsertion procedure, and the cochleas prepared for histopathologic analysis. Long-term implantation of the electrode resulted in a relatively mild tissue response within the cochlea. Results also showed that inner and outer hair cell survival, although significantly reduced adjacent to the array, was normal in 8 of the 10 cochleas apicalward. Moreover, the electrode reinsertion procedure did not appear to adversely affect this apical hair cell population. Significant new bone formation was frequently observed in both control and reimplanted cochleas close to the electrode fenestration site and was associated with trauma to the endosteum and/or the introduction of bone chips into the cochlea at the time of surgery. Electrode insertion trauma, involving the osseous spiral lamina or basilar membrane, was more commonly observed in reimplanted cochleas. This damage was usually restricted to the lower basal turn and resulted in a more extensive ganglion cell loss. Finally, in a number of cochleas part of the electrode array was located within the scala media or scala vestibuli. These electrodes did not appear to evoke a more extensive tissue response or result in more extensive neural degeneration compared with electrodes located within the scala tympani. In conclusion, the present study has shown that the reimplantation of a multichannel scala tympani electrode array can be achieved with minimal damage to the majority of cochlear structures. Increased insertion trauma, resulting in new bone formation and spiral ganglion cell loss, can occur in the lower basal turn in cases where the electrode entry point is difficult to identify due to proliferation of granulation and fibrous tissue.en_US
dc.relation.ispartofScientific publications, vol.8, 1994-1995, no.711en_US
dc.subjectcochlear pathologyen_US
dc.subjectscala tympanien_US
dc.subjectelectrode arrayen_US
dc.subjectmacaqueen_US
dc.subjectauditory nerve fibersen_US
dc.subjectcochlear implanten_US
dc.subjectmonkeyen_US
dc.subjectupper basal turnen_US
dc.subjecthair cell survivalen_US
dc.subjectnew bone formationen_US
dc.subjectendosteumen_US
dc.subjectelectrode insertion traumaen_US
dc.subjectosseous spiral laminaen_US
dc.subjectbasilar membraneen_US
dc.subjectganglion cellen_US
dc.subjectscala mediaen_US
dc.subjectscala vestibulien_US
dc.titleCochlear pathology following reimplantation of a multichannel scala tympani electrode array in the macaqueen_US
dc.typeJournal Articleen_US
melbourne.source.titleAmerican Journal of Otologyen_US
melbourne.source.monthMarchen_US
melbourne.source.volume16en_US
melbourne.source.issue2en_US
melbourne.source.pages186-199en_US
melbourne.elementsidNA
melbourne.contributor.authorClark, Graeme
melbourne.contributor.authorShepherd, Robert
melbourne.contributor.authorPYMAN, BRIAN
melbourne.accessrightsOpen Access


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