|- candidate number||28538|
|- NTR Number||NTR7017|
|- ISRCTN||ISRCTN no longer applicable|
|- Date ISRCTN created|
|- date ISRCTN requested|
|- Date Registered NTR||6-feb-2018|
|- Secondary IDs||ABR NL 54761.068.15 METC 162006|
|- Public Title||Vestibular implantation and inner ear preservation|
|- Scientific Title||Monitoring of auditory and vestibular function during destructive labyrinth surgery|
|- Healt Condition(s) or Problem(s) studied||Bilateral vestibulopathy, Vestibular implant, Destructive labyrinth surgery|
|- Inclusion criteria||- Having a disease that requires destructive surgery of the labyrinth|
- Having residual hearing that can be monitored using Auditory Brainstem Response (ABR)
- >18 years old
- Giving informed consent
|- Exclusion criteria||- Mentally incapacitated patients|
- Carrier of any other implanted electronic device (e.g. pace-maker)
- Having an enlarged vestibular aqueduct on routinely made preoperative CT-scan
- Not being able to obtain an ABR signal at the outpatient department
|- mec approval received||yes|
|- multicenter trial||yes|
|- control||Not applicable|
|- Type||Single arm|
|- planned startdate ||1-mrt-2018|
|- planned closingdate||30-nov-2020|
|- Target number of participants||10|
|- Interventions||Routine labyrinthectomy with temporary electrode insertion |
The surgeon will use the routine retro-auricular approach with mastoidectomy and exposition of the labyrinth, typical for destructive surgery of the labyrinth. Electrodes will be inserted into the labyrinth (specifically the semicircular canals) to evaluate insertion, manipulation and placement of the electrode design. Auditory function is evaluated through ABR and electrocochleography (ECochG) at every step of the surgery. After electrode manipulation inside the canals, the electrodes will be activated. Vestibular function in response to electrical stimulation will be measured. Afterwards the electrodes are taken out again.
The recordings will add at most 30 minutes to the destructive surgery. After the recordings, the whole labyrinth will be destructed as planned according to the initial surgery. Typically, the labyrinths would be disposed as medical waste, but here they will be fixed with paraformaldehyde and sent for histopathological examination.
|- Primary outcome||1. Assessment of preserved auditory function when the membranous labyrinth is kept intact.|
2. Assessment of preserved auditory function after the membranous labyrinth is perforated with an electrode, which closes the opening directly.
3. Assessment of preserved auditory function after electrode manipulation.
4. Assessment of preserved auditory function after vestibular implantation, i.e. opening of the whole labyrinth and leakage of endolymph.
|- Secondary outcome||5. Assessment of preserved vestibular function for different electrode positions with an electrode inside the semicircular canals.|
6. Assessment of damage on tissue and cellular level with histopathological examination of labyrinths.
|- Timepoints||Ad 1. During surgery. After opening the bony semicircular canal (but leaving the membranous labyrinth inside the semicircular canal intact)|
Ad 2. During surgery. After inserting an electrode inside the semicircular canal.
Ad 3. During surgery. After manipulation of the electrode inside the semicircular canal.
Ad 4. During surgery and after surgery. After opening the whole labyrinth with leakage of endolymph.
Ad 5. During surgery. After electrode placement (and before extensive electrode manipulation).
Ad 6. After surgery. Specimens of labyrinths are sent for histopathologic examination directly after surgery.
|- Trial web site|
|- CONTACT FOR PUBLIC QUERIES|| Joost Stultiens|
|- CONTACT for SCIENTIFIC QUERIES|| Joost Stultiens|
|- Sponsor/Initiator ||Academic Hospital Maastricht (azM)|
(Source(s) of Monetary or Material Support)
|MED-EL, Academic Hospital Maastricht (azM)|
|- Brief summary||Bilateral vestibular loss represents a major handicap with strong balance disturbances, higher risk of fall, visual symptoms
(oscillopsia) and a loss of autonomy.|
Prognosis is poor and treatment options are limited. At this moment, the department of ORL of Maastricht University Medical
Center is working on a vestibular implant. Aim is to (partially) restore vestibular function.
However literature about hearing preservation during vestibular implantation is scarce. Until now, hearing preservation is only
proven in a few animals. Humans who underwent implantation, were already deaf (our previous study) or lost hearing as a
result of implantation (Washington group). The surgical technique and electrodes currently used, are not able to preserve
hearing. Therefore surgical technique and electrode design must be improved in order to be able to implant people with
(sub)normal hearing. This study investigates an improved surgical technique, together with a new electrode design and
histopathological examination of implanted inner ears, aimed at preservation of hearing and vestibular function.
|- Main changes (audit trail)||Group: there is only one group.|
|- RECORD||6-feb-2018 - 22-feb-2018|