Sensorineural hearing loss, Cochlear implantation Hearing loss, Cochlear implantation
Conditions
Interventions
Participants will be randomized to one of two surgical approaches: extended
round window or cochleostomy.
Sponsors
Radboud Universitair Medisch Centrum
Eligibility
Age
18 Years to 64 Years
Inclusion criteria
Inclusion criteria: • Participants >18 years old with post-lingual unilateral or bilateral sensorineural hearing loss • CI candidate based on local criteria • Cochlear implantation with a Cochlear Ltd. Slim Modiolar Electrode (CI632) • Preoperative 500 Hz pure-tone threshold <80 dB hearing level under headphones in the ear to be implanted.
Exclusion criteria
Exclusion criteria: • Previous or existing cochlear-implant recipients. • Patients with prelingual hearing loss. • Patients with mixed hearing loss (air bone gap) • Ossification or other cochlear anomaly that might prevent complete electrode array insertion. • Abnormal cochlear nerve anatomy on preoperative CT or MRI (excluding a Mondini malformation or large vestibular aqueduct syndrome) • Deafness due to lesions of the acoustic nerve or central auditory pathway. • Diagnosis of auditory neuropathy. • Active middle ear infection. • Medical or psychosocial conditions that would contraindicate participation in study evaluations. • Unrealistic expectations from the participant regarding the possible benefits, risks, and limitations inherent to the CI procedure and the investigation.
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Primary outcome measure: The difference per group between pre- and postoperative (3-month) pure tone thresholds, averaged at 500, 750 and 1000 Hz (PTAlow). A difference in change of the PTAlow between approaches (CO or eRW) that exceeds 15 dB is regarded clinically significant. | — |
Secondary
| Measure | Time frame |
|---|---|
| • The difference between pre- and postoperative (1 week and 12 months) pure tone thresholds, averaged at 500, 750 and 1000 Hz (PTAlow), • Promontory ECochG threshold estimates at 500 Hz at the following stages of surgery: a) after facial recess, b) after drilling RWM overhang, c) after completion of the approach to implantation (CO or eRW), d) after sheath insertion, e) after electrode array insertion, f) after sheath withdrawal and g) after electrode lead positioning. The compound-action potential (CAP) thresholds will be reported over time. The effect of each surgical stage on residual hearing will be inferred a shift in threshold. This approach may identify whether residual hearing is damaged prior to insertion of the electrode. • The position of electrode contacts relative to the modiolus, and the angular depth of insertion, and as assessed with pre- and post-operative CT-scan (TBD with HRCT-scans or UHRCT-scans and combined with micro-CT images, according to EIORL methodology). The trajectory of the electrode is expected to differ between the two surgical approaches. To assess whether this is the case, the position of each electrode contact (its angular dept of insertion and the distance of each electrode contact) will be measured, and the group measurements compared. • Electrode measurements: TIM and NRT. If the electrode positions differ so may the thresholds of the eCAPs elicited by each electrode array. Therefore, the thresholds, plotted for each electrode along the array, will be compared between groups. Similarly, any electrode position between groups might be reflected in different profiles of the Trans Impedance Matrix. | — |
Countries
Belgium, Netherlands
Contacts
Public ContactJ.J. Lindeboom
Radboud Universitair Medisch Centrum
Outcome results
None listed