Cochlear implant surgery
The cochlear implant procedure is usually considered a minimally invasive surgery. A cochlear implant is a medical device that can partially restore hearing. The implant directly stimulates the auditory nerve to appreciate the sense of sound. A cochlear implant is a computerized device that enables hearing in people with ‘nerve deafness’ by stimulating the hearing nerve with coded electrical signals. It bypasses damaged hair cells of the cochlea (the cause of ‘nerve deafness’ in most people). Cochlear implant surgery is usually performed under general anesthesia. The procedure may take 2-4 hours to complete. During the surgery, the surgeon will:
- Make a minimally invasive incision measuring approximately 2.5 inches behind the ear.
- Once an incision is made, a pocket is made in the bone to secure the implant package and protect it.
- The surgeon identifies the facial nerve and explores to reveal the cochlea.
- Once the cochlea is revealed, the surgeon may insert the implant electrodes into the cochlea.
- The surgeon then places a receiver behind the ear and secures it to the skull and closes the incisions.
- A dressing is placed over the ear for 24 hours. The operation is minimally painful, requiring pain relief only on the day of surgery in many instances.
- Self-dissolving stitches are used. There is minimal swelling and bruising, and the skin incision heals within 2 weeks. Antibiotics are prescribed for 1 week.
- The implant site needs a few weeks to heal. Then, it can be activated by the doctor. The doctor will help you adjust to the settings and fine-tune or map it so that you feel comfortable with the implant.
Cochlear implants work by processing sound signals and transmitting them to a receiver that is implanted behind the ear. The receiver will then transfer the signals to electrodes that are implanted in the inner ear. These signals stimulate the auditory nerve, which directs the signals to the brain. The brain will translate the signals as sounds to help you hear. Although cochlear implants can help patients hear better, they do not restore hearing or completely cure hearing loss.
Advantages of having a cochlear implant include:
- Hearing speech at a normal sound level
- Understanding speech without having to observe the lips
- Being able to hear someone talk on the phone
- Hearing music better
- Distinguishing different levels of sound
- Being able to speak more clearly, so others can understand
Complications may include:
- Severe bleeding
- Side effects associated with anesthesia
- Nerve damages that can cause changes to sense of taste or weakness in the face
- Balance issues
- Tinnitus (ringing in the ears)
- Fluid leaks in and around the brain
- Meningitis (infection of the lining around the brain that is rare but serious)
Recovery from cochlear implant surgery
After cochlear implant surgery, the patient may experience any of the following side effects:
- Pressure or discomfort in the affected ear
- Confusion or feeling disoriented
- Sore throat from the breathing tube
The patient may go home 1-2 days after surgery. After discharge, the doctor will encourage you to:
- Keep the bandages on for a specified time.
- Schedule an appointment to remove stitches approximately one week after the implant.
- Follow instructions on how to care for the stitches, wash your head, and shower, as well as what should your diet be.
- Schedule a follow-up appointment to activate the implant approximately 3-6 weeks after the surgery. After 3 weeks of healing, the cochlear implant is activated. Postimplantation therapy is required for the patients to adapt to hearing sounds. The patient will also undergo a hearing test performed by the rehabilitation team as part of the scheduled follow-up appointment process.
The outcome of cochlear implant surgery
The outcome varies from person to person. Factors that can affect the outcomes of cochlear implantation include the patient’s age when the hearing was lost and the period between hearing loss and cochlear implant surgery. For children, the best results generally occur with getting a cochlear implant at a young age. For adults, the best results are generally associated with a shorter period of profound hearing loss before cochlear implantation. Adults with little or no experience with sound tend to benefit less from cochlear implants. Most patients reported diminished tinnitus (ringing or buzzing sound) after cochlear implantation.