Impedance, neural response telemetry, and speech perception outcomes after reimplantation of cochlear implants in children.

Objective: To compare mean impedance levels, neural response telemetry (NRT), and auditory perception after initial and explant-reimplant pediatric cochlear implants.

Study Design: Retrospective case review.

Setting: Tertiary referral hospital and cochlear implant program.

Patients: Children 0 to 16 years inclusive who have undergone explant-reimplant of their cochlear implant.

Intervention: Impedance levels, NRT, and speech perception performance.

Main Outcome Measures: Impedance, NRT, and auditory perception at switch on, 3 months, 12 months, 3 years, and 5 years after initial cochlear implant and reimplantation.

Results: The explant-reimplant group receiving Cochlear contour array had significantly (p < 0.001) raised impedance at switch on, 3 months, 12 months, and 3 years, compared with their initial implant. The explant-reimplant group receiving Cochlear straight array had marginally significant (p = 0.045) raised impedance at switch on, 3 months, 12 months, and 3 and 5 years. Infection was associated with greater increases in impedance in the reimplant Contour group. NRT was increased in the explant-reimplant group but not significantly (p = 0.06). Auditory perception returned to preexplant levels within 6 months in 61% of children.

Conclusion: Impedance is higher after explant-reimplant and remains increased for years after explant-reimplant with Cochlear contour and to a lesser degree the straight array device.