Influence of an intraoperative perilymph gusher on cochlear implant performance in children with labyrinthine malformations.

OBJECTIVES To assess the effect of an intraoperative perilymph fluid gusher during cochlear implantation on speech perception abilities in pediatric patients with labyrinthine anomalies. SETTING Tertiary care academic referral center. METHODS Seventy subjects with labyrinthine malformations who received a cochlear implant were identified in our pediatric cochlear implant database. In 30 cases, an intraoperative perilymph fluid gusher was encountered during surgery. Fifteen children with GJB2 positive hereditary hearing loss served as controls. Multiple speech perception measures were obtained with the cochlear implant. The best score for each subject over time was determined as a speech reception index in quiet. This index was compared among groups and malformation types. RESULTS The speech reception index in quiet demonstrated overall good performance scores of cochlear implantation in children with incomplete partitioning/enlarged vestibular aqueduct type malformations. Children with hypoplastic malformations, on the other hand, showed variable outcomes with many children demonstrating only limited long-term speech discrimination abilities. The presence or absence of a perilymph gusher did not significantly influence results after cochlear implantation. CONCLUSION This report documents the variable outcomes of pediatric cochlear implantation in children with inner ear malformations. More importantly, anatomic parameters, such as the classification of the anomaly and the presence of a viable cochlear nerve, seem to influence performance measures substantially. The presence of a perilymph gusher did not influence outcomes in both hypoplastic and incomplete partitioning/enlarged vestibular aqueduct type malformations. LEVEL OF EVIDENCE 2b Individual retrospective cohort study.