Surgical factors in pediatric cochlear implantation and their early effects on electrode activation and functional outcomes

OBJECTIVE:: To assess the impact of surgical factors on electrode status and early communication outcomes in young children in the first 2 years of cochlear implantation. STUDY DESIGN:: Prospective multicenter cohort study. SETTING:: Six tertiary referral centers. PATIENTS:: Children 5 years or younger before implantation with normal nonverbal intelligence. INTERVENTION:: Cochlear implant operations in 209 ears of 188 children. MAIN OUTCOME MEASURES:: Percent active channels, auditory behavior as measured by the Infant Toddler Meaningful Auditory Integration Scale/Meaningful Auditory Integration Scale and Reynell receptive language scores. RESULTS:: Stable insertion of the full electrode array was accomplished in 96.2% of ears. At least 75% of electrode channels were active in 88% of ears. Electrode deactivation had a significant negative effect on Infant Toddler Meaningful Auditory Integration Scale/Meaningful Auditory Integration Scale scores at 24 months but no effect on receptive language scores. Significantly fewer active electrodes were associated with a history of meningitis. Surgical complications requiring additional hospitalization and/or revision surgery occurred in 6.7% of patients but had no measurable effect on the development of auditory behavior within the first 2 years. Negative, although insignificant, associations were observed between the need for perioperative revision of the device and 1) the percent of active electrodes and 2) the receptive language level at 2-year follow-up. CONCLUSION:: Activation of the entire electrode array is associated with better early auditory outcomes. Decrements in the number of active electrodes and lower gains of receptive language after manipulation of the newly implanted device were not statistically significant but may be clinically relevant, underscoring the importance of surgical technique and the effective placement of the electrode array.