Cochlear Electrical Impedance and the Effect of Topical Dexamethasone on Cochlear Implant Surgery
Status:
Unknown status
Trial end date:
2018-11-01
Target enrollment:
Participant gender:
Summary
Hearing is the ability to perceive sounds through the ear. If the transmission of sound is
defective, the person suffers some degree of hearing loss. Cochlear Implants (CI) provide
partial hearing by stimulating auditory nerve cells.
The evaluation of the functionality of the CI is facilitated by several analysis tools, such
as the clinical calibration software. This offers the possibility of measuring electrical
impedances in the cochlea. The electrical impedance is the opposition to the current flow
between two electrodes. It is composed of two main elements: resistance and reactance. The
impedances in a cochlear implant are not stable over time. The value is minimal immediately
after surgery, and increases progressively in the first 2 to 3 weeks after the procedure due
to the immune response of the organism against a foreign body and the trauma of the array
insertion. Several authors have suggested the use of topical or intravenous corticosteroids
to decrease intracochlear fibrosis. The use of Dexamethasone could have a protective effect
by reducing the initial inflammatory response, apoptosis, and delayed fibrosis, which could
impact the impedance.
There is limited evidence on the effect of intra-surgical topical corticosteroids on the
impedance of the cochlear implant.
The aim of this clinical trial is to evaluate the impact of topical dexamethasone on the
electrical impedance of the cochlear implant, with special attention to the analysis of the
capacitive component. It will be carried out through an experimental, prospective, randomized
and double-blind study.
Objective To determine whether the use of topical dexamethasone in a single dose applied in
the tympanic cavity (middle ear) during cochlear implant surgery modifies the capacitive
component of the electrical impedance of the electrodes in the cochlea before the activation
of the cochlear implant.
Material and methods A phase 3 clinical trial will be conducted. The design is a parallel,
randomized, controlled and double-blind experimental study.
Expected impact The use of local dexamethasone during cochlear implant surgery would decrease
the inflammatory response, improving postoperative impedances.