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Cochlear Implantation in the Guinea Pig
Published on: June 15, 2018
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Influence of electrode array stiffness and diameter on hearing in cochlear implanted guinea pig
Mylène Drouillard1,2, Renato Torres1,2, Elisabeth Mamelle1,2
1Sorbonne Universités, Université Pierre et Marie Curie Paris 6, Inserm, Unité "Réhabilitation chirurgicale mini-invasive et robotisée de l'audition", Paris, France.
Plos One
|August 25, 2017
Summary
To preserve hearing during cochlear implantation, a flexible and thin electrode array is crucial. This study found that less stiff, thinner arrays resulted in better hearing outcomes and lower insertion forces in guinea pigs.
Area of Science:
- Otolaryngology
- Biomedical Engineering
- Neuroscience
Background:
- Cochlear implantation aims to restore hearing but carries risks of damaging cochlear structures and residual hearing.
- Electrode array design and insertion mechanics are critical factors influencing surgical outcomes and hearing preservation.
Purpose of the Study:
- To evaluate the impact of electrode array physical parameters (stiffness, diameter) on residual hearing and cochlear integrity during insertion.
- To identify optimal array characteristics for minimizing trauma and preserving hearing in cochlear implant surgery.
Main Methods:
- Three electrode array prototypes with varying stiffness and external diameters were implanted in guinea pigs using a robotic insertion tool.
- Insertion forces were recorded, and auditory brainstem response (ABR) was used to assess hearing preoperatively and at 7 and 30 days post-implantation.
- Cochlear anatomy was examined post-mortem to assess array position and identify any associated fibrosis.
Main Results:
- Arrays with lower stiffness and smaller external diameters (0.3 mm) resulted in significantly better hearing outcomes compared to stiffer, larger arrays (0.4R).
- Higher insertion forces were recorded for the stiffer, larger array (0.4R), correlating with poorer hearing results.
- Incorrect array positioning or cochlear fibrosis were associated with significant hearing loss (≥40 dB at 16 kHz).
Conclusions:
- Flexible and thin electrode arrays, along with precise placement within the scala tympani, are essential for preserving residual hearing during cochlear implantation.
- Minimizing insertion trauma and preventing post-operative fibrosis are key objectives for successful hearing outcomes.
