Skip to Main content Skip to Navigation
Journal articles

Damage to inner ear structure during cochlear implantation: Correlation between insertion force and radio-histological findings in temporal bone specimens

Abstract : Cochlear implant insertion should be as least traumatic as possible in order to reduce trauma to the cochlear sensory structures. The force applied to the cochlea during array insertion should be controlled to limit insertion-related damage. The relationship between insertion force and histological traumatism remains to be demonstrated. Twelve freshly frozen cadaveric temporal bones were implanted with a long straight electrodes array through an anterior extended round window insertion using a motorized insertion tool with real-time measurement of the insertion force. Anatomical parameters, measured on a pre-implantation cone beam CT scan, position of the array and force metrics were correlated with post-implantation scanning electron microscopy images and histological damage assessment. An atraumatic insertion occurred in six cochleae, a translocation in five cochleae and a basilar membrane rupture in one cochlea. The translocation always occurred in the 150-to 180-degree region. In the case of traumatic insertion, different force profiles were observed with a more irregular curve arising from the presence of an early peak force (30 ± 18.2 mN). This corresponded approximately to the first point of contact of the array with the lateral wall of the cochlea. Atraumatic and traumatic insertions had significantly different force values at the same depth of insertion (p < 0.001, two-way ANOVA), and significantly different regression lines (y ¼ 1.34x þ 0.7 for atraumatic and y ¼ 3.37x þ 0.84 for traumatic insertion, p < 0.001, ANCOVA). In the present study, the insertion force was correlated with the intracochlear trauma. The 150-to 180-degree region represented the area at risk for scalar translocation for this straight electrodes array. Insertion force curves with different sets of values were identified for traumatic and atraumatic insertions; these values should be considered during motorized insertion of an implant so as to be able to modify the insertion parameters (e.g axis of insertion) and facilitate preservation of endocochlear structures.
Complete list of metadatas

Cited literature [49 references]  Display  Hide  Download

https://www.hal.inserm.fr/inserm-01671750
Contributor : Sandrine Maurice <>
Submitted on : Friday, December 22, 2017 - 3:39:13 PM
Last modification on : Wednesday, August 19, 2020 - 11:18:19 AM

File

 Restricted access
To satisfy the distribution rights of the publisher, the document is embargoed until : jamais

Please log in to resquest access to the document

Identifiers

Citation

Daniele de Seta, Renato Torres, Francesca Russo, Evelyne Ferrary, Guillaume Kazmitcheff, et al.. Damage to inner ear structure during cochlear implantation: Correlation between insertion force and radio-histological findings in temporal bone specimens. Hearing Research, Elsevier, 2017, 344, pp.90 - 97. ⟨10.1016/j.heares.2016.11.002⟩. ⟨inserm-01671750⟩

Share

Metrics

Record views

276