Quantitative imaging analysis of transcanal endoscopic Infracochlear approach to the internal auditory canal.

Objective: A transcanal endoscopic infracochlear surgical approach to the internal auditory canal (IAC) in a human temporal bone model has previously been described. However, the proportion of patients with favorable anatomy for this novel surgical technique remains unknown. Herein, we perform a quantitative analysis of the transcanal endoscopic infracochlear corridor to the IAC based on computed tomography.

Methods: High resolution computed tomography scans of adult temporal bones were measured to determine the accessibility of the IAC when using an endoscopic transcanal, cochlear-sparing surgical corridor.

Results: This approach to the IAC was feasible in 92% (35 of 38) specimens based on a minimum distance of 3mm between the basilar turn of the cochlear and the great vessels (jugular bulb and carotid artery).

Conclusions: Infracochlear access to the IAC is feasible in the majority of adult temporal bones and has implications for future hearing preservation drug delivery approaches to the IAC.