The Effect of Round Window Sealants on Delayed Hearing Loss in a Guinea Pig Model of Cochlear Implantation

Abstract

Delayed, low-frequency hearing loss was observed when cochleae were sealed with muscle or periosteum, but not when cochleae were sealed with fibrin glue.

Effect of cochlear implantation on middle ear function: A three‐month prospective study

“…Recent animal CI hearing preservation experiments by Rowe et al 7,8 were able to replicate delayed lowfrequency hearing loss following CI in the guinea pig. Muscle and periosteal round window sealants were associated with thickening of the round window and fixation of the stapes through fibrosis and ossification, and so the delayed hearing loss was likely to be conductive in nature.…”

“…Recent animal CI hearing preservation experiments by Rowe et al were able to replicate delayed low‐frequency hearing loss following CI in the guinea pig. Muscle and periosteal round window sealants were associated with thickening of the round window and fixation of the stapes through fibrosis and ossification, and so the delayed hearing loss was likely to be conductive in nature . Clinically, ossicular fixation with conductive hearing loss caused by bone dust collecting on the ossicular chain has been reported following endolymphatic sac decompression surgery .…”

“…Muscle and periosteal round window sealants were associated with thickening of the round window and fixation of the stapes through fibrosis and ossification, and so the delayed hearing loss was likely to be conductive in nature. 8 Clinically, ossicular fixation with conductive hearing loss caused by bone dust collecting on the ossicular chain has been reported following endolymphatic sac decompression surgery. 11 Therefore, CI surgery could theoretically increase impedance at the stapes footplate by fibrosis, ossification, or bone dust ankylosis, resulting in delayed conductive hearing loss due to stapes fixation.…”

“…This hearing loss was speculated to result from progressive fibrosis at the round window affecting cochlear mechanics, consistent with Choi and Oghalai's model. A subsequent animal model study by Rowe et al revealed that delayed low‐frequency hearing loss following insertion of an electrode array through the round window was associated with fibrosis at the round window, and in particular the stapes, which lies close to the electrode. A corollary of these considerations is that sound conduction to or within the inner could become more impeded as fibrosis and scar tissue affecting the ossicular chain and/or scala tympani matures.…”

Hearing Preservation with the Slim Modiolar Electrode Nucleus CI532® Cochlear Implant: A Preliminary Experience

“…Other authors also suggest that cochlear implantation can be performed either via RW or cochleostomy with similar outcomes and results [Adunka et al, 2014]. According to previous experience, delayed, low-frequency HL was observed when cochleae were sealed with muscle or periosteum, but not when cochleae were sealed with fibrin glue [Rowe et al, 2016]. We choose to use this material for sealing the cochlear approach.…”