Cochlear implantation in postirradiated ears: outcomes and challenges

Radiotherapy to head and neck tumors can potentially damage the auditory pathways. This has relevance in cochlear implants and there is a need for clinical studies to confirm the feasibility of cochlear implantation in these patients.

The records of all patients who had received cochlear implants at our institution were reviewed in this retrospective study and those who had prior irradiation for head and neck tumors were further studied. Case controls consisted of comparable cochlear implant recipients who did not have prior radiotherapy.

Four of 230 patients met the criteria for further study. They had received radiotherapy for nasopharyngeal carcinoma 11 to 28 years ago and the postimplant follow-up period ranged from 9 to 46 months. The implanted ear of each patient had favorable preoperative promontory stimulation results. Postimplant, all patients were satisfied with their hearing outcomes and the improvement in speech discrimination scores was comparable to the controls. These cases also illustrated specific clinical concerns, including 1) radiation-induced endocrine dysfunction was common and, if overlooked, could result in increased anesthetic risks, and 2) irreversible eustachian tube dysfunction led to chronic middle ear problems, which complicated surgery; the use of modified surgical techniques overcame these difficulties.

Deafened postirradiated patients with nasopharyngeal carcinoma were able to achieve good postimplant hearing outcomes comparable to those of nonirradiated patients. Should cochlear implantation be indicated in patients who have had prior radiation to the head and neck, specific preoperative, intraoperative, and postoperative issues have to be addressed.