Occasionally a manufacturer identifies a systematic problem with an implant, and will remove the device from the market until the issue has been resolved. Other regulatory issues may also temporarily halt availability of a device.
The United States Food and Drug Administration maintains a database of events with the devices that it regulates. In government speak, it is known as the Manufacturer and User Facility Device Experience. The acronym that you have a chance of remembering is MAUDE. It can be very tedious to review the data manually. Fortunately for you, cochlearimplantHELP.com monitors the database and provides you with periodic updates and analyses.
While cochlear implants are very reliable devices, occasionally it may be necessary to remove one and replace it. This may be due to device failure, or due to a medical issue.