Summary of MedSun Reports Describing Adverse Events Concerning Cochlear Implants
MedSun: Newsletter #44, January 2010

A cochlear implant is a small, complex electronic device that can help to provide a sense of sound to a person who is profoundly deaf or severely hard-of-hearing. The implant consists of an external portion that sits behind the ear and a second portion that is surgically placed under the skin (see figure). An implant has the following parts:

-A microphone, which picks up sound from the environment.
-A speech processor, which selects and arranges sounds picked up by the microphone.
-A transmitter and receiver/stimulator, which receive signals from the speech processor and convert them into electric impulses.
-An electrode array, which is a group of electrodes that collects the impulses from the stimulator and sends them to different regions of the auditory nerve.
An implant does not restore normal hearing. Instead, it can give a deaf person a useful representation of sounds in the environment and help him or her to understand speech. [1]

Over the past 2 years, MedSun has received 9 adverse event reports associated with cochlear implant devices from the following 2 manufacturers: Advanced Bionics LLC (5) and Cochlear Americas (4). The reports were submitted by 5 hospitals between July 2007 and July 2009.

The reported device problems were:
• Defective electrodes (4)
• Makes distracting buzzing noise (1)
• Bone growth over device (1)
• Device failed impedance testing (1)
• Electronic chip in device failed (1)


Of the reports that listed patient age, 3 had a patient age listed as less than 21 years and 5 had a patient age listed as greater than 21 years. Of the reports that listed patient gender, a total of 2 reports involved female patients and a total of 5 reports involved male patients.

These MedSun reports contributed to FDA awareness of the device problems.


[Note: The reports have been edited for clarity]

Adverse Event Reports
Device Device Identifiers (model, catalogue number, lot) Event Description
Cochlear Americas/Nucleus Freedom Nucleus Contour device/None /None Patient with a history of traumatic brain injury and hearing loss status post his trauma. He had minor benefit after cochlear implantation and the implant was found to have defective electrodes.
Cochlear Americas/Nucleus Freedom CI24RE/None/None Patient is an adolescent with bilateral cochlear implants. His right side was implanted when he was a toddler. His left side was implanted ~3 years ago. More recently, his older right implant has been functioning poorly for him. It does not provide him with useful sound and makes distracting noises. He notes that last fall, he began noticing a "bumblebee" bubbling sound in the right cochlear implant. In spite of adjustments to his MAPS, this would not go away. He had his processor upgraded on the right and this did not improve things. He now feels that he cannot tolerate this. He wears his processor so that he does not get in any trouble, but leaves it turned off. His parents are very frustrated with this. They want him to benefit from both implants. They also feel that there has been a recent decline in his performance in school, which they think might be due to his right implant not being utilized. He underwent integrity tests by Cochlear Corporation ~5 months ago. The test was interpreted as normal. Recently, the patient came in to have his existing right side device explanted, and replaced with a new one. The device was explanted as defective and sent to Biomedical Engineering.
Advanced Bionics LLC/HiRes 90K Cochlear Implant C1-1400-01/None/None Per explanting surgeon the device was known to fail. Surgeon had been notified several years ago by the manufacturer of a voluntary recall. We waited until the device did fail before removing and replacing it with a new cochlear implant.
Cochlear Americas/Nucleus Contour (Freedom)-Cochlear CI24RE(CA)/None/None Patient underwent left cochlear implantation ~3.5 years ago. Patient's outcome with the implant was never very good and it deteriorated as time when on. Subsequent integrity testing revealed an extensive electrode abnormality.
Cochlear America/cochlear implant None/ REF Z60353 (Z6060353)/None After it was implanted, the cochlear implant device impedance was not measurable. It was subsequently explanted, and the surgeon used device back-up, which was supplied for this patient. No harm to patient.
Advanced Bionics Corporation/HiRes 90K Cochlear Implant CI-1400-01/None/None The chip in the Bionics cochlear implant was having problems, per patient's MD.
Advanced Bionics Corporation/Hi Resolution Bionic Ear System CI-1400-02H/None/G0994 One of the apical electrodes was unusually rotated. The tip of the electrode was not straight even with the stylet in place. Unable to proceed with implant placement.
Advanced Bionics Headquarters/Clarion-cochlear implant AB-5100r right/None/None Patient had a right cochlear implant performed using the Clarion 1.2 device eight years ago. After a satisfactory initial performance, patient suffered a recent device failure and presents for elective revision surgery. There was dense new bone formation over the mastoid and the feedthrough of the cochlear implant electrode. The device itself appeared normal upon extraction. There was a slight recurrence of slow outflow of cerebrospinal fluid from the cochleostomy after the implant electrode was extracted.
Advanced Bionics Corporation/cochlear implants C124RE-005/None/None The right cochlear implant showed gradual device malfunction and failed integrity testing. Patient presented for an elective revision of the implant. The electrodes were damaged during the extraction of the implant. The implant was then extracted from the cochleostomy site without difficulty.




The above list of reports may or may not have contributed to the following device recalls


Recall Information
Product NameRecall Class Date Posted Recalling Firm Reason for Recall
HR90K Platinum Series Headpiece Model Number AB-7300-001 ADVANCED BIONICS LLC 12740 San Fernando Rd.... 2 Feb-03-2009 Advanced Bionics LLC Mistuned headpiece - Advanced Bionics recently became aware of a tuning issue with some Platinum Series and S-Series headpieces shipped from May 2007 through April 2008. Tuning refers to the process through which the headpiece's communication frequency is adjusted to match that of the internal device. Potential clinical symptoms include: -No lock -Intermittent lock -Implant locks, but cann
Platinum Series Headpiece Model Number AB-7300. The headpiece is used in conjunction with speech pr... 2 Feb-03-2009 Advanced Bionics LLC Mistuned headpiece - Advanced Bionics recently became aware of a tuning issue with some Platinum Series and S-Series headpieces shipped from May 2007 through April 2008. Tuning refers to the process through which the headpiece's communication frequency is adjusted to match that of the internal device. Potential clinical symptoms include: -No lock -Intermittent lock -Implant locks, but can
GSI Audera (version 2.6 software) Viasys Healthcare, Inc. Part or (Catalog) Numbers: 2001-9700, 2... 2 Nov-12-2008 Cardinal Health, Inc GSI Audera systems requires a system software update due to issues with the Split-Screen and the Vestibular Evoked Myogenic Potential (VEMP) functions. A. Split Screen Field Correction: GSI Audera units with version 2.6 software may mislabel Auditory Evoked Potential (AEP) waveform responses with respect to the identification of the stimulus ear.

Additional Information:

[1] National Institution on Deafness and Other Communication Disorders. (2007). Cochlear Implants. Retrieved July 28, 2009. Website:
http://www.nidcd.nih.gov/health/hearing/coch.asp.


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