Cochlear Implants, Hearing Loss, Sensorineural
Conditions
Keywords
Surgical approach, Round Window, Cochleostomy, Electrocochleography, Imaging, Residual hearing preservation
Brief summary
This is a prospective multicenter multinational randomized control trial. The duration of the study for the individual patient will be approximately 1 year (pre-operative assessments, 1 week, 3 months and 12 months follow-up assessments). Participants will be randomized to one of two surgical approaches: eRW or CO, with a 1:1 allocation in a parallel design.
Detailed description
Rationale: Preserving residual hearing in cochlear implant (CI) surgery has gained significant attention. It not only signifies minimally invasive implantation but also supports natural sound perception and enables electrical-acoustic stimulation, enhancing sound localization, music appreciation, and speech recognition in noisy environments. Using the Cochlear™ Nucleus® CI with Slim Modiolar electrode (Cochlear Ltd., Sydney, Australia), potential sites of residual hearing loss in surgery include approaches to the cochlear lumen, potential damage during entry, and damage during electrode insertion. Studies comparing different surgical approaches (cochleostomy (CO) and extended round window (eRW)) show varied results. Electrocochleography (ECochG) can be used to indicate intracochlear damage during electrode insertion, however, the variability observed in ECochG responses during cochlear implantation remains significant. Moreover, ECochG has not yet been used to monitor cochlear functions throughout every phase of surgery, including the insertion of the sheath or stabilization of the electrode lead. Objective: The aim of this study is to investigate whether the type of surgical approach to the cochlea; CO or eRW using the CI632 affects the final residual hearing and secondarily, intracochlear trauma and electrode position, as determined by pure tone audiometry, EcochG and imaging. Study population: Adult CI candidates with post-lingual onset of severe to profound hearing loss, who are scheduled to receive a Nucleus CI632 with a slim modiolar electrode array and have a preoperative audiometric low-frequency average air conduction threshold of \<80 decibel (dB) hearing level at 500 Hz in the ear to be implanted.
Interventions
PROCEDURESurgical approach: cochleostomy or extended round window
Surgical placement of a cochlear implant electrode array
Sponsors
GZA Ziekenhuizen Campus Sint-Augustinus
Universitaire Ziekenhuizen KU Leuven
Radboud University Medical Center
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Individuals aged 18 years and older who have clinically established post-linguistic sensorineural hearing loss. * CI candidate based on local or national reimbursement criteria. * Cochlear implantation with a CI632. * Preoperative 500 Hz pure-tone air conduction threshold \<80 dB hearing level (HL) in the ear to be implanted. * Willing and able to provide written informed consent.
Exclusion criteria
* Previous or existing CI recipient. * Ossification or other anatomical abnormalities of the cochlea or its windows possibly affecting normal electrode array insertion. * Abnormal cochlear nerve anatomy on preoperative CT or MRI. * Subjects who are unable to undergo CT or MRI. * Deafness due to acoustic nerve or central auditory pathway lesions. * Diagnosis of auditory neuropathy. * Active middle ear infection. * Additional handicaps that would prevent participation in study evaluations. * Unrealistic expectations from the participant regarding the possible benefits, risks, and limitations inherent to the CI procedure and the investigation. * Cochlear employees or employees of Contract Research Organisations or contractors engaged by Cochlear for the purposes of this investigation.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Residual hearing | 3-months postoperatively | The difference in residual hearing per group (eRW or CO) between pre- and postoperative pure tone thresholds, averaged at 500, 750 and 1000 Hz (PTAlow). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| ECochG thresholds after multiple surgery stages | Intraoperatively | ECochG thresholds with a promontory recording electrode after the following surgery stages: a) posterior tympanotomy (baseline), b) drilling for RW membrane exposure, c) completion of the approach to implantation (CO or eRW), d) sheath insertion, e) electrode array insertion, f) sheath withdrawal, and g) positioning of the electrode lead. |
| Intracochlear electrode position | 3-months postoperatively | The position of electrode contacts relative to the modiolus and the angular insertion depth (AID), as assessed with pre- and post-operative CT-scan. |
Countries
Netherlands
Contacts
Primary ContactCoby Lindeboom, MD
Backup ContactEmmanuel Mylanus
Outcome results
None listed