Temporal bone histopathology in revision cochlear implantation

Abstract

An increasing number of young infants, as early as six months of age with congenital hearing loss receive cochlear implantation, and it is probable that many of these patients will require revision surgery later in life. The possibility of explantation of the cochlear electrode and reimplantation may cause damage to the cochlea, compromising the speech perception outcome in revision implant is of concern. There is only one prior temporal bone histopathology study to look at the outcome of revision surgery and no prior study evaluating revision cochlear implantation that used the round window approach. We conducted a histopathological study of four temporal bone specimens from four patients who underwent revision cochlear implantation and when available post-operative speech perception tests were evaluated. In all cases, the reimplanted electrode followed into the same fibrous sheath without evidence of additional intracochlear damage due to revision surgery. The intracochlear damage from the initial cochlear implantation appears to be a more important factor in outcomes rather than changes associated with explantation and reimplantation.

Keywords:

• Cochlea
• Cochlear Implant
• Reimplantation
• Histopathology
• Fibrosis
• Osteogenesis

Additional information

Notes on contributors

Alden F. Smith

Alden F. Smith is an Assistant Professor from the Department of Otolaryngology – Head & Neck Surgery, Loma Linda University.

Gail Ishiyama

Gail Ishiyama is a Professor from the Department of Neurology, UCLA.

Ivan A. Lopez

Ivan A. Lopez is an Adjunct Professor from the Department of Head & Neck Surgery, UCLA.

Akira Ishiyama

Akira Ishiyama is a Professor from the Department of Head & Neck Surgery, UCLA.