Minimizing hearing loss: A novel surgical approach for round window exposure in miniature pigs

Abstract

Background

A delicate operation for exposing the round window without affecting the hearing function is critical for auditory research. Despite the different surgical approaches proposed for miniature pigs, hearing protection during operation is still challenging. The efficient solution to this problem is significant for accurate auditory research.

New method

Eight healthy Diannan miniature pigs, aged three months and of both sexes, with normal hearing, were utilized. Three pigs were employed for anatomical studies. Based on the findings from these anatomical investigations, we propose the facial nerve medial approach designed to expose the round window while preserving hearing function in the porcine model. The remaining five pigs were used to verify the surgical approach and hearing function.

Results

The anatomy study confirmed that the lateral side of the round window was the genu of the facial nerve. Removing the medial wall of the genu part of the facial nerve canal allows access to the tympanic cavity and exposes the round window. The facial nerve medial approach effectively exposed the round window in vivo, with no significant change in auditory brainstem response threshold immediately post-operation.

Comparison with existing methods

The facial nerve medial approach to exposing the round window preserved the sound transmission structures of the ear, maintaining hearing function post-operation.

Conclusions

The facial nerve medial approach with a retroauricular incision allows access to the tympanic cavity and exposes the round window without impacting hearing, making it ideal for accurate auditory research in miniature pigs.