Electrode extrusion through the tympanic membrane in a pediatric patient

Abstract

The medical literature contains an increasing number of reports that establish the safety of cochlear implantation in both adults and children. Complications, however, are not inexistent, with reported rates between 3% and 13% for major complications and 7% to 37% for minor complications. 1 Though the exact definitions vary between series, major complications are generally defined as those that require surgical intervention or result in permanent disability, whereas minor complications include those managed conservatively or with a simple procedure (eg, aspiration). 1-3 Although device exposure through the postauricular skin flap is not uncommon, only a limited number of reports describe extrusion of the electrode through the tympanic membrane. In this case report, we present a child who developed a retraction pocket with electrode extrusion six years after implantation. The patient is a 17-year-old girl who presented to our clinic at age 13, two years after right cochlear implantation at a different institution for progressive hearing loss. The patient was then lost to follow-up for three years when she presented with right otalgia. She denied any history of recent infections and had no signs of implant malfunction. Examination of her right ear revealed an anteriorinferior retraction pocket, with obvious visualization of the cochlear implant electrode through the tympanic membrane. After informed consent was obtained, the patient was taken back to the operating room for exploration. This revealed a retraction pocket with the electrode extruding through the membrane into the external canal in a loop fashion (Fig 1). The middle ear was full of granulation tissue. The stimulating electrode had advanced through the facial recess into the mesotympanum, eroding the malleus and the tympanic membrane and protruding into the canal (Fig 2). All 22 leads were still in the cochlea. The device was carefully freed of the surrounding scar tissue and repositioned back into the mastoid cavity. A cartilage tympanoplasty was then performed. The internal receiver was in place and did not require manipulation. One year after the procedure, the tympanic membrane appears intact with no evidence of retraction or cholesteatoma. DISCUSSION