A cochlear implant (CI) is an electronic device that provides a sense of sound to individuals with severe to profound sensorineural hearing loss. Unlike traditional hearing aids, the CI system bypasses damaged parts of the inner ear, directly stimulating the auditory nerve with electrical signals. Because this technology involves a surgically placed component, many people question its permanence and whether it can be removed. Understanding the distinct roles of its separate components clarifies the answer.
Understanding Cochlear Implant Components
The cochlear implant system has two main parts: an external unit and an internal unit. The external part is worn by the user and is easily removable without surgery. This unit contains the microphone, the speech processor (which digitizes and codes the sound), and the transmitting coil.
The internal part is secured beneath the skin behind the ear during a surgical procedure. This component consists of the receiver/stimulator, which is a small package that receives coded signals from the external coil. Attached to the receiver is the electrode array, a thin wire threaded into the cochlea, the snail-shaped structure of the inner ear. This internal device is intended to be a permanent fixture.
Is the Internal Device Removable
The internal component of a cochlear implant can be surgically removed, a procedure known as explantation. Although the device is designed for a lifetime of use, medical circumstances or the need for an upgrade sometimes require its removal. Explantation is a surgical procedure, though it is often less extensive than the original implantation surgery.
The process requires general anesthesia, and a surgeon makes an incision behind the ear to access the implanted receiver and disconnect the components. While the main body of the implant is removed, the electrode array may sometimes remain in the cochlea. If the entire array is to be removed, it requires careful surgical expertise to gently pull the wire out of the delicate inner ear structure.
Scenarios Requiring Device Removal
The decision to remove a cochlear implant is usually prompted by specific medical or hardware-related issues. The most frequent reason for explantation is a malfunction or failure of the internal device itself. Technical issues, such as hard failure where the device completely stops working, necessitate removal and often replacement.
Another significant category of reasons is medical complications, particularly infections at the implant site. A severe infection of the skin flap overlying the implant, or a deeper infection like mastoiditis, often requires temporary removal of the hardware to fully resolve the issue. Other rare medical causes include severe hematoma or spontaneous extrusion of the device.
Less commonly, explantation occurs due to personal choice, such as dissatisfaction with the hearing outcome or a desire to transition to a different technology. In cases where the device is removed due to failure or to allow for a technology upgrade, the explantation is often immediately followed by a re-implantation of a new device.
Hearing Status Following Explantation
The removal of a cochlear implant does not restore the original hearing function, as the device was installed to bypass existing damage. The implantation surgery itself often causes the loss of any remaining natural hearing, known as residual hearing, in the implanted ear. Consequently, if a CI is removed and not immediately replaced, the individual typically reverts to the profound level of hearing loss they had prior to the initial surgery.
In many cases of explantation, a new device is promptly re-implanted once the underlying issue, such as an infection, has been resolved. Re-implantation is a common and successful strategy, particularly when the explantation was due to hardware failure. If re-implantation is not an option, the person will rely on their other ear or utilize non-surgical aids like traditional hearing aids or other assistive listening devices.