Cochlear implantation in the paediatric population is now an accepted method of rehabilitating profoundly or totally deaf children. The problems of cochlear implantation in children with other significant medical problems are examined. A retrospective review of the records of the first 45 children implanted at our centre was carried out. The review focused on surgical factors and outcome in addition to variations in technique which have occurred since the programme began. Congenital hearing loss was the most common indication for implantation. Fifteen children (33 per cent) had other medical problems. Three cases of flap breakdown (two occurring after direct trauma to the package bed) and one case of a misplaced electrode requiring re-implantation accounted for the only major complications to date. Minor complications included hypertrophic scar formation and post-operativewound infection. All children were using their implants at the time of this review, but two have subsequently been explanted. Cochlear implantation of children with multiple medical problems requires acceptance of a slightly higher risk of complications.

We present a unique case in which a multichannel cochlear implant device was explanted and the same device was re-implanted into the contralateral ear. A patient with bilateral total deafness secondary to head injury received an implant in his left ear but developed severe facial nerve stimulation. Because this stimulation could not be eliminated effectively with change of programming, it was decided to implant the contralateral ear. Since the device itself was functioning well, it was explanted from the left ear and re-implanted successfully into the right ear. Facial nerve stimulation was minimal in this ear and the patient demonstrated very good speech discrimination. To our knowledge, this is the first description of this strategy.

We present a cochlear implant failure previously unidentified and unreported. Following successful implantation and activation of a Cochlear Mini 22 system, a distressing barrage of crackling noises was heard by the patient despite repeated programming with threshold and comfort level adjustment. The implant soon became nonfunctional and integrity testing showed deficient electrical responses and abnormal surface measured wave forms. Investigation of the explant, following reimplantation with an identical system, showed a defective trim capacitor, an electric component of the internal circuit in the stimulator. Paired Student's t-test showed a marginally significant increase (p = 0.047) in effective threshold level and a highly significant decrease (p = 0.0002) in maximum comfort level for the second implant compared to the first implant.