Cochlear implantation is used to restore hearing in patients with severe hearing loss. Cochlear implantation can be applied from 1 year old. Preoperative evaluation is of great importance for proper patient selection. Cochlear implants are more successful in patients who are younger and whose hearing loss occurs after the period of speech learning.
Cochlear implants have two parts: Internal part consisting of receiver and cochlear electrodes, external part consisting of external speech processor and transmitter. Cochlear implant helps hearing in patients with severe hearing loss by providing electrical stimulation of the cochlear nerve. The external processor of the cochlear implant picks up sounds and converts them into electrical impulses. These stimuli are transmitted transcutaneously to the receiver and via the receiver to the electrodes in the cochlea. Electrical signals reaching the cochlea depolarize the cochlear nerves and allow the perception of sounds. Cochlear implant application is a teamwork where otolaryngologists, audiologists and speech pathologists work together.
The criteria that the pediatric cochlear implant candidate should bear:
Children aged over 12 months (1 year old)
Severe hearing loss
Expecting greater benefit from hearing aid
Family support, sufficient motivation, realistic expectations
Providing rehabilitation and educational support for speech and language development
– Since patients will receive general anesthesia, they should have appropriate health conditions for surgery and general anesthesia. Audiological evaluation should be made on patients.
– Adult patients with severe hearing loss who cannot benefit from the hearing aid sufficiently are also candidates for cochlear implants.
– Hearing levels of pediatric patients should be evaluated with the ABR test. Information should be obtained from the family about children’s behavior towards sound.
It is important whether the patient loses his hearing before or after language development. Since the patient’s previous history of meningitis may prevent cochlear implant placement, information should be obtained on this issue.
The presence of findings indicating middle ear infection such as hole in the eardrum, retraction should be detected. Has the patient had previous ear surgery? It should be questioned. Active middle ear disease should be ruled out. Although cochlear implants can be placed in patients who have undergone surgery due to chronic middle ear disease, the operation becomes a little more difficult.
High resolution temporal bone tomography should be performed before all cochlear implant operations. With tomography, information about inner ear morphology, cochlea, position of facial nerve, facial recess size, height of jugular bulbus, and thickness of parietal bone in young children can be obtained. In order for all electrodes to be placed, the cochlea should be of normal structure and their rotation should be monitored. Mondini malformation of the cochlea does not allow insertion of all electrodes. However, it does not create an obstacle for the implant. Previous meningitis may disrupt the structure of the cochlea with fibrosis and ossification and prevent the electrode placement. Magnetic Resonance Imaging is helpful in evaluating whether the cochlea is open and the presence of the cochlear nerve after meningitis in children who are candidates for cochlear implantation. Imaging techniques are also important in evaluating the width of the internal acoustic canal.
Audiometric examination with and without a hearing aid for candidates who are considered to have a cochlear implant is helpful in the evaluation. Complete cochlear implant evaluation should be done by a trained audiologist.
Cochlear implant is a very good option in the treatment of severe hearing loss in patients with appropriate expectations.
The cochlear implant is placed by surgery in the mastoid bone area behind the ear. For this, a mastoidectomy is performed. The facial recess area between the facial nerve and the external ear canal is opened. A round window is observed from here. After rounding the round window niche, a cochleostomy is performed and electrodes are placed in the cochlea. The recipient is placed posterior to the auricle, adjacent to the mastoid cavity. Subsequently, the surgical area is closed. A few weeks after healing, the outer piece is placed, activated, and adjusted.
Facial nerve palsy can be seen at a rate of 0.4% depending on the surgery. Electrodes can be damaged by 1.2%. Tinnitus and dizziness can be seen after surgery, but subsides afterwards. Rarely, meningitis can be seen. In this case, antibiotic therapy is given intravenously. If the implant fails or breaks, it must be reinserted.
Postoperative anterior posterior skull radiography can be used to check whether the electrodes are located in the cochlea. A mastoid dressing is applied to the mastoid area for compression. The wound area is controlled with postoperative follow-up. Facial nerve functions are checked. After the operation, Magnetic Resonance Imaging cannot be done without removing the internal magnet part of the receiver.
Vaccination should be done for Pneumococcus and influenza to prevent meningitis. Postoperative antibiotic treatment should be given.
Programming of the electrodes can begin 2 weeks after the operation. However, programming is usually done 4-5 weeks after adequate wound healing.
Today, cochlear implant application can be performed bilaterally simultaneously.
Open yourself to a whole new world of medical travel, and discover the beautiful places and healthcare experiences that await you around the globe!
Medicatürk focusing only on a seamless patient journey, helping patients on their travels from beginning to end.