Cochlear implant surgery is an invasive procedure, meaning it involves entering the body by making an incision. The operation requires cutting through skin and bone to place an internal component of the device inside the skull and inner ear. A cochlear implant is an electronic medical device that provides a sense of sound for individuals with significant hearing loss who do not benefit from traditional hearing aids. It works by bypassing damaged portions of the inner ear to stimulate the auditory nerve directly.
The goal of the procedure is to restore partial hearing. This surgical intervention sets the stage for a process of hearing rehabilitation that continues long after the operation is complete.
The Cochlear Implant Surgical Procedure
The surgical process for a cochlear implant is a precise operation performed under general anesthesia that lasts between one and four hours. It begins with the surgeon making a small incision behind the ear to access the underlying mastoid bone. This bone is located in the skull just behind the ear and provides a pathway to the middle and inner ear.
Once the mastoid bone is exposed, the surgeon uses a drill to create an opening. This opening creates a secure bed for the implant’s internal receiver and provides a direct route to the cochlea. The cochlea is the spiral-shaped, fluid-filled structure in the inner ear housing the nerve endings for hearing. The surgeon then makes a tiny opening into the cochlea itself.
With access established, the surgeon carefully threads a thin, flexible tube containing electrode arrays into the cochlea’s chambers. This electrode array delivers electrical signals to the auditory nerve. The internal receiver is then placed under the skin in the space created in the mastoid bone. Finally, the surgeon closes the incision with sutures and applies a protective dressing.
Surgical Risks and Potential Complications
Like any surgery, the cochlear implant procedure carries potential risks, though complications are rare. Beyond the general risks of anesthesia, infection, bleeding, or swelling, there are complications specific to the surgery’s location. Because the procedure involves the inner ear, some risks are unique to this operation.
The facial nerve, which controls movement on one side of the face, passes through the ear, and while injury is very rare, it is a possibility. The inner ear also houses the vestibular system responsible for balance, so some patients may experience temporary dizziness or vertigo. Other potential side effects include:
- Tinnitus, which is a ringing sound in the ear
- A temporary change in taste that resolves over time
- Loss of any residual natural hearing in the operated ear
- Device malfunction that may require a second surgery for repair or replacement
The Recovery and Healing Process
Recovery begins immediately after the procedure is finished. Patients are observed for several hours as they wake from anesthesia and may be discharged the same day or stay overnight. A bandage or head dressing will cover the incision site, and any mild to moderate pain is managed with oral pain medication for a few days.
Over the next few weeks at home, physical healing is the primary focus. Swelling around the incision site is normal and will gradually subside. Patients are given specific instructions on how to care for the wound, which includes keeping it clean and dry. Activity restrictions are common, and patients are advised to avoid strenuous exercise and swimming for several weeks to allow the area to heal fully.
A follow-up appointment with the surgeon is scheduled about one week after the operation. During this visit, the surgeon will inspect the incision to ensure it is healing properly and may remove any stitches. Most people can return to their routine activities within about a week, though full healing of the surgical site takes approximately three to four weeks.
Post-Surgical Device Activation
The final step in the cochlear implant process is activating the device, often called the “switch-on.” This non-invasive appointment with an audiologist takes place three to six weeks after surgery, once swelling has resolved. This waiting period ensures the external components of the device will fit correctly.
During the activation, the external components, including the microphone and speech processor, are fitted. The audiologist then programs the implant in a process known as “mapping.” This involves adjusting the electrode settings to the individual’s comfort and perception levels, marking the first time the recipient experiences sound through the implant.
The initial sounds may not be clear, as it takes time for the brain to learn how to interpret the new electrical signals. This begins a period of auditory rehabilitation involving follow-up appointments for programming adjustments. Working with audiologists and speech therapists helps the recipient adapt to the implant and associate meaning with the sounds they hear.