Utility of Intraoperative Computed Tomography for Cochlear Implantation in Patients with Difficult Anatomy

Objective And Importance: To describe cases that illustrate the utility of intraoperative computed tomography (CT) in cochlear implantation of patients with difficult temporal bone anatomy.

Clinical Presentation: A 2-year-old male with congenital X-linked stapes gusher syndrome and a 2-year-old female with enlarged vestibular aqueduct underwent successful cochlear implantation with the help of intraoperative CT. In the latter case, the initial intraoperative C-arm fluoroscopy suggested malposition of the electrode, however, was not able to provide details for adjustments. In both cases, intraoperative CT changed the insertion technique of the operating surgeon and allowed for improved electrode positioning. A 47-year-old female with polyostotic fibrous dysplasia and a 55-year-old male with post-meningitis near-total cochlear obliteration underwent successful cochlear implantation with confirmation of electrode position with intraoperative CT. In the former case, the image-guided navigation system was also implemented. Finally, a 72-year-old female underwent cochlear implantation during which intraoperative C-arm fluoroscopy suggested intra-cochlear insertion. However, postoperative CT showed the electrode extending into the internal auditory canal (IAC), illustrating the limitations of C-arm fluoroscopy.

Intervention: Intraoperative CT imaging and image-guided navigation system.

Conclusion: When faced with challenging temporal bone anatomy, intraoperative CT can provide critical details of the patient's microanatomy that allows for improved localization of the electrode and adjustments in operative techniques for successful cochlear implantation.