Surgical approach for complete cochlear coverage in EAS-patients after residual hearing loss

Autoři: Nora M. Weiss aff001;  Anandhan Dhanasingh aff002;  Sebastian P. Schraven aff001;  Marko Schulze aff003;  Soenke Langner aff004;  Robert Mlynski aff001
Působiště autorů: Dept. of Otorhinolaryngology, Head and Neck Surgery,”Otto Koerner”Rostock University Medical Center, Rostock, Germany aff001;  MED-EL, Innsbruck, Austria aff002;  Rostock University Medical Center, Institute of Anatomy Gertrudenstraße, Rostock, Germany aff003;  Institute of Diagnostic and Interventional Radiology, Pediatric and Neuroradiology, Rostock University Medical Center, Rostock, Germany aff004
Vyšlo v časopise: PLoS ONE 14(9)
Kategorie: Research Article
doi: 10.1371/journal.pone.0223121



In cases with residual-hearing (RH) loss after cochlear implantation, a safe method is needed to provide full spectral resolution and as much auditory information as possible without implant replacement. Aim of this study was to prove the feasibility of accessing a partially inserted cochlear-implant-electrode for complete insertion to its maximum length through the external ear canal using a transcanal approach.


Two CI electrodes were customized with 18 stimulating channels. The electrode design enables the use of 12 active channels available for electrical stimulation inside the cochlea both after partial and full insertion. 10 CI electrodes were implanted in 10 fresh human cadaveric temporal bones. After initial partial insertion by posterior tympanotomy, the electrode was inserted to its maximum length via a transcanal approach. Radiographs and CT scans were performed to confirm the electrode position. The electrodes were investigated via x-ray after removal.


X-ray and CT-scans confirmed the electrode prototypes covering an angular insertion depth between 236° to 307° after initial insertion. Accessing the electrode in the middle ear space was feasible and insertion to its full length was successful. Post-insertion CT confirmed insertion of the 28mm and 31.5mm electrode arrays covering an angular insertion depth between 360° and 540° respectively. No tip foldovers were detected.


This study confirms the feasibility of extending the electrode insertion to its maximum insertion length using a transcanal approach in temporal bone specimens. This constitutes a second stage procedure on demand in EAS-surgery. This may be beneficial for EAS-patients providing electrical stimulation beyond the basal turn of the cochlea once the functional residual hearing is lost, without replacing the entire CI.

Klíčová slova:

Cochlea – Deafness – Functional electrical stimulation – Medical implants – Middle ear – Surgical and invasive medical procedures – Prototypes – Surgeons


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2019 Číslo 9

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