Download 13th International Conference on Cochlear Implants and Other

yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Document related concepts

Auditory system wikipedia, lookup

Audiology and hearing health professionals in developed and developing countries wikipedia, lookup

Earplug wikipedia, lookup

Olivocochlear system wikipedia, lookup

Dysprosody wikipedia, lookup

Sensorineural hearing loss wikipedia, lookup

Noise-induced hearing loss wikipedia, lookup

Hearing loss wikipedia, lookup

Speech perception wikipedia, lookup

Telecommunications relay service wikipedia, lookup

Navigation-guided transmodiolar approach for auditory nerve implantation via middle ear in human
Sobhy W.F. , Guigou C. , Mazalaigue S. , Ricolfi F. , Camuset J.-P. , Bozorg Grayeli A.
CNRS UMR-6306, Electronic,Image and Computer Research Laboratory, Dijon, France, 2Dijon Hospital University, Otolaryngology-Head
and Neck Surgery, Dijon, France, 3Collin, Bagneux, France, 4Dijon Hospital University, Department of Neuroradiology, Dijon, France, 5Point
Medical Imaging Center, Dijon, France
Objectives: Auditory nerve implantation appears as an interesting alternative to cochlear implantation since it
reduces the electrical consumption and enhances tonotopy in the cochlear nucleus. This implantation raises
technical issues since modiolus could not be accessed in its whole length in a reproducible manner, and to our
knowledge, this approach has never been reported in clinical studies. The aim of this study was to investigate
the feasibility of a navigation-guided approach to modiolus through middle ear cavities in human.
Materials and methods: Six adult human temporal bone specimens (3 left and 3 right) were included in this
study. In each specimen, 4 titanium screws were placed in the mastoid cortex and served as fiducial markers. A
high-resolution CT-scan was then performed. Images were loaded on the neuronavigation system (Digipointeur,
Collin, Bagneux, France). The system was coupled to a piezoelectric drill equipped with an angled insert
(Mectron, Bois-D'Amon, France). After a radical mastoidectomy and removal of malleus and incus, the drill (1
mm diameter) entered cochlear apex and progressed in the modiolar axis. Its position was monitored in real-time
by neuronavigation. A stainless steel wire (0.6 mm diameter) used as a sham electrode array was introduced in
the modiolar axis. All specimens underwent a CT-scan after the procedure. In the second part of the study, 122
temporal bone CT scans from patients were analyzed for anatomical parameters relevant to this approach.
Results: The transmodiolar approach was feasible in all temporal bones. However, the angle of the insert did
not allow an optimal trajectory in all cases and consequently, the entry point was slightly deviated backward from
the modiolar axis in 2 temporal bones. The array was completely implanted down to the inner end of the
modiolus in 4 temporal bones with an average intracochlear length of 3.6 ± 1.11 mm and partially in the 2
remaining specimens. The mean vector distance of the target accuracy at the entry point (√(X +Y +Z )) was
0.065 ± 0.0583 mm. The study of anatomical parameters relevant to transmodiolar approach on CT-scans
showed a significant inter individual variability. The modiolar length or orientation did not seem to be influenced
by age, but the distances between the cochlear apex and the posterior aspect of the carotid wall or the
temporomandibular joint were shorter in children than in adults.
Conclusions: A transmodiolar approach through middle ear cavities for an auditory nerve implantation is
feasible in human under neuronavigation. Anatomical parameters relevant to this approach in children show a
modiolar length and orientation similar to adults but shorter distances to neighboring anatomical barriers.