Successful Cochlear Implantation for Intracochlear Fibrosis

Abstract

Intracochlear fibrosis is a rare disorder that can lead to hearing loss and make cochlear implantation challenging. The etiology of intracochlear fibrosis is diverse, including infections, inflammation, and past surgical procedures. The condition causes ossification and scar tissue growth within the cochlea, leading to progressive obstruction of the cochlear turn. High-resolution computed tomography (HRCT) and magnetic resonance imaging (MRI) are sensitive diagnostic modalities for fibrosis and ossification. There is a paucity of information in the literature regarding cochlear implantation during the fibrotic stage. This case report discussed the presentation, diagnosis, and surgical management of intracochlear fibrosis in a patient with a history of sudden and severe hearing loss. A 44-year-old female patient with a 20-year history of sudden profound sensorineural hearing loss (SNHL) in both ears was successfully treated with cochlear implantation. Thorough preoperative planning for cochlear implantation, including HRCT and MRI cochlear protocol, is crucial for identifying intracochlear fibrosis, which can be missed on routine audiometry. She underwent a surgery for right cochlear implantation using postauricular approach. Drilling was done to the round window niche, and we removed an abnormal, chalky white bone we encountered by continuing to drill this abnormal bone following the scale tympani until we identified the opening of the scala tympani, then we inserted the cochlear implant device. She was doing well on the subsequent post-operative follow-up. Intracochlear fibrosis treatment with cochlear implantation has proven successful in several studies. Audiologic outcomes vary with time to implantation, so an early attempt should be made for cochlear implantation. Follow-up is important to monitor auditory outcomes.

Keywords: cochlear implantation; inracochlear fibrosis; otology; scala tympani; sensorineural hearing loss.

Figure 1. Audiogram test for the mentioned patient revealing profound-degree SNHL on both sides.

SNHL: sensorineural hearing loss

Figure 2. (a-c): axial CT scan of the left cochlea, and (d-f): coronal CT scan of the left cochlea. Both views revealed the cochlea with relatively confluent hyperdense plaque of mineralization in the basal and middle turns just proximal to the round window.

AT: apical turn. BT: basal turn.

Figure 3. Post-operative audiological assessment for the right ear with spectacular result.