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Updated: May 26, 2026
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A Surgical Procedure for the Administration of Drugs to the Inner Ear in a Non-Human Primate Common Marmoset (Callithrix jacchus)
Published on: February 27, 2018
Promontorial cochleostomy in nonhuman primates. Is it atraumatic?
Raquel Manrique1, Sebastián E Picciafuoco, Francisco Javier Cervera-Paz
1Department of Otolaryngology, University of Navarra Hospital & Medical School, Pio XII s/n., Pamplona, Navarra, 31008, Spain. rmanrique@unav.es
Summary
This study demonstrates that surgical access to the inner ear, including cochleostomy, can be performed in Macaca fascicularis without causing hearing loss. Auditory function remained intact throughout the 27-month follow-up period, validating the surgical approach.
Area of Science:
- Otolaryngology
- Neurosurgery
- Auditory Neuroscience
Background:
- Surgical approaches to the inner ear require precise techniques to preserve delicate auditory structures.
- Evaluating the functional impact of surgical interventions on hearing is crucial for clinical success.
Purpose of the Study:
- To assess the feasibility of surgical access to the inner ear in an animal model without inducing hearing loss.
- To validate surgical techniques for exposing the membranous labyrinth and cochlea.
Main Methods:
- Five Macaca fascicularis underwent mastoidectomy, posterior tympanotomy, and promontorial cochleostomy (four subjects).
- Hearing was evaluated using distortion-product otoacoustic emissions (dPOAE) and auditory brainstem responses (ABR) pre- and post-surgery.
- Long-term follow-up (27 months) monitored auditory function.
Main Results:
- Distortion-product otoacoustic emissions remained present at all follow-up points (3, 6, 12, 24, 26 months).
- Auditory thresholds measured by ABR in cochleostomy subjects stayed within the normal 20-30 dB range at 27 months.
- Surgical exposure of the endosteal layer and membranous labyrinth did not result in measurable hearing deficits.
Conclusions:
- Surgical approaches to the inner ear, specifically cochleostomy, are feasible in Macaca fascicularis without compromising hearing function.
- These findings support the clinical application of surgical techniques aimed at accessing the cochlea while preserving hearing.
- The study provides evidence for the safety and efficacy of specific otologic surgical procedures in an animal model.
