Improved auditory performance of cochlear implant patients using the middle fossa approach

Area of Science:

• Otolaryngology
• Neurosurgery
• Biomedical Engineering

Background:

• Profound bilateral hearing loss presents significant challenges for auditory rehabilitation.
• Traditional transmastoid cochlear implant approaches may be limited in certain complex ear anatomies.
• The middle fossa approach offers an alternative surgical route for cochlear implantation.

Purpose of the Study:

• To evaluate the preliminary outcomes of cochlear implantation using a middle fossa approach.
• To assess the efficacy of this technique in patients with various complex aetiologies of hearing loss.
• To compare speech recognition results with the traditional transmastoid approach.

Main Methods:

• A cohort of nine patients with profound bilateral hearing loss underwent cochlear implantation via a middle fossa approach.
• A small cochleostomy was created on the basal turn of the cochlea.
• Different cochlear implant systems with single and double electrode arrays were used.
• Intraoperative testing included telemetry and electrically evoked auditory brainstem responses (EABR).

Main Results:

• Patients demonstrated improved speech recognition compared to those who underwent the transmastoid approach.
• The middle fossa approach is suitable for patients with conditions like radical mastoidectomy cavities and adhesive otitis media.
• Single arrays stimulated more cochlear turns, potentially enhancing spiral ganglion cell survival; double arrays allowed for full cochlear coverage.

Conclusions:

• Cochlear implantation via the middle fossa approach is a viable and effective technique for selected patients.
• This method provides advantages in cochlear coverage and stimulation of viable neural elements.
• The middle fossa approach may represent an elective option for optimal cochlear implantation outcomes.