Cochlear implant surgery

The insertion of a cochlear implant is considered a routine operation for a surgeon specialising in otolaryngology or audiology. Like any surgical operation, it is not without risk, but it is a simple procedure requiring only a small incision of 4 to 5 cm behind the ear.

Many factors influence the outcome of a cochlear implant procedure. Today, thanks to constant advances in audiological technology, choosing a cochlear implant is an excellent way of remedying profound deafness and moderate to severe hearing loss. The most common risk factors are:

• possible episodes of mastoiditis or otitis media;
• possible damage to the facial nerve or eardrum;
• episodes of loss of balance and dizziness, often temporary;
• risk of infection, a frequent complication of all types of surgery.

Depending on whether the implant is placed in one or both ears, it is referred to as a unilateral or bilateral cochlear implant. In both cases, the decision will be based on whether the deafness is unilateral or bilateral, and on the patient's day-to-day needs.

There are several types of cochlear implant, depending on the nature of the patient's hearing loss. The most common implants are:

• bone conduction devices, which convert sound into vibrations that are sent to the inner ear via the outer and middle ear;
• middle ear implants, which pick up sound and convert it into vibrations that are transmitted to the middle ear and then to the inner ear;
• auditory implants placed in the brain stem, which convert sound into signals sent to the brain via the auditory nerve.

Before a cochlear implant is fitted, preliminary clinical examinations are necessary to assess your eligibility. These include:

• audiological tests such as tone and speech audiometry;
• assessment of hearing aid performance in people already fitted with a hearing aid;
• computer tomography and/or magnetic resonance imaging;
• standard examinations prior to an operation under general anaesthetic.