COCHLEAR IMPLANTATION IN CONGENITALLY DEAF CHILDREN WITH ISOLATED LARGE VESTIBULAR AQUEDUCT: A SURGEON’S PERSPECTIVE

Abstract

Background: The vestibular aqueduct is a bony canal containing the endolymphatic duct. Its average diameter is 0.6 to 1.5 mm at its midpoint between the crus communes and its opening at the posterior cranial fossa. If the radiographic diameter at this point is more than 1.5 mm, it is considered a case of large vestibular aqueduct (LVA). It is the most common radiographically detectable inner ear anomaly in congenital hearing loss. LVA with hearing loss is described as LVA syndrome (LVAS). In children with LVA, cochlear implantation has been proven to be effective in increasing both auditory perception and speech and language development. Material and methods: The study was carried out from March 2009 to March 2014 on 9 isolated LVAS cases among 406 congenitally deaf children who had been implanted at the Madras ENT Research Foundation (MERF), Chennai, India. This observational study is focused on pre-operative assessment, surgical issues, and postoperative follow-up. Results: Five males and four females less than six years old were detected with LVAS. There was a pulsatile stapes in five cases and a CSF gusher in eight cases. CSF gushers were well controlled during surgery by tightly sealing the insertion site with soft tissue. An intraoperative mannitol drip was used in six patients and fibrin glue in three. Postoperative oral acetazolamide was used routinely in cases of CSF gusher. No early postoperative complications were seen. Intraoperative impedance and neural telemetry were all satisfactory. Conclusions: Cochlear implantation in LVAS is feasible and effective. However, CSF gushers are common and require appropriate management and follow-up.