Telmesani Radiological Classification of the Location of the Vertical Segment of the Facial Nerve: Impact on Surgical Approach in Cochlear Implant Surgery.

OBJECTIVE

This study was conducted to establish a radiological classification of the location of the vertical segment of the facial nerve (VSFN) and to see if this has implications on the surgical technique needed to access the round window niche (RWN) in cochlear implant (CI) surgery.

STUDY

DESIGN

Observational case series study.

SETTING

Tertiary referral center.

PATIENTS: One hundred twenty seven patients underwent CI surgery, and high resolution computed tomography (HRCT) of 140 temporal bones was studied. The data that were collected consisted of the patient's age, sex, radiological inner ear malformations (IEM), and the surgical technique used to access the RWN.

MAIN OUTCOME MEASURES: The radiologic location of the VSFN in relation to the lateral semicircular canal in the coronal plane of HRCT and its implication on the surgical approach used to access the RWN in CI surgery.

RESULTS

A statistically significant association is present between the radiological location of the VSFN and the surgical approach used (p < 0.001).There was insignificant correlation between the locations of the VSFN and the patient's age, sex, and IEM as the p > 0.05.

CONCLUSIONS

On HRCT (0.6 mm) in the coronal plane, the position of the VSFN in relation to the lateral semicircular canal is correlated with the alternative approaches that must be taken during CI surgery.