Cochlear implantation in the irradiated temporal bone

Abstract

Objective: To demonstrate the feasibility and complexities of cochlear implantation in the setting of bilateral temporal bone osteoradionecrosis.Study design: Case report.Setting: Tertiary care referral centre.Case description: A 66-year-old woman with bilateral temporal bone osteoradionecrosis and profound hearing loss, following treatment for tonsillar cancer, underwent cochlear implantation. Prior canal wall down mastoidectomy and subsequent temporal bone resection with free flap reconstruction had been performed on the implanted ear. The contralateral ear received a canal wall down mastoidectomy. A completely dehiscent mastoid segment of the facial nerve and extensive fibrosis were evident in the implanted ear. Only minimal fibrous reaction was found within the cochlea, allowing for full electrode insertion. At three months, speech recognition testing documented a consonant-nucleus-consonant (CNC) word score of 54 per cent.Conclusions: This report demonstrates the feasibility of cochlear implantation after temporal bone surgery and free flap reconstruction in the setting of diffuse osteoradionecrosis. The patient's excellent open-set speech understanding using the cochlear implant implies that radiation did not severely damage the central auditory pathways. Thus, some patients with radiation-induced hearing loss may be appropriate cochlear implant candidates. Special attention should be paid to surgical planning, as complications related to wound healing, electrode insertion and facial nerve injury may be more likely.