Cochlear implantation in children with anomalous cochleovestibular anatomy

Objective: The aim of the study is to assess the audiological and surgical outcome after cochlear implantation in children with inner ear malformation and to compare them with a group of congenitally deaf children implantees without inner ear malformation.

Introduction: Children with profound sensorineural deafness with malformations of the inner ear represent a challenge, accounting to 5-15% of congenital sensorineural deafness. These cases were originally regarded as a contraindication for cochlear implant surgery.

Methods: Retrospective study of 26 patients with congenital inner ear malformation, from a total population of 329 cochlear implant patients. Radiological evaluation with high resolution computed tomography and magnet resonance was performed to all patients in order to evaluate all the preoperative conditions. All patients were tested using European Portuguese word discrimination tests (monosyllabic test, number test and sentences test), capacity of auditory performance (CAP) and speech intelligibility rating (SIR).

Results: In all 7.9% of deaf children in our center study have inner ear abnormalities. All children underwent successful implantation. CAP yielded an average 7.1 (+/-1.7), SIR 4.3 (+/-1.0). The children without inner ear abnormalities did not achieve statistically significant better scores. Two children had a perilymph gusher, and there were no other complications.

Conclusion: Cochlear implantation can be successfully performed in children with inner ear malformation. Audiological performance after cochlear implantation in malformed inner ears is comparable to that found in other congenitally deaf patients. The risk of CSF leak is associated with inner ear abnormalities and should be anticipated during surgery.