The common cavity vs incomplete partition type I conundrum: Decision making and management with the cochlear implant form electrode

Abstract

It has been seen that 20% of children with deafness have inner ear malformations. Studies demonstrate that Cerebrospinal Fluid (CSF) leakage occurs in 40–50% of patients with inner ear malformations. Differentiating between the various malformations pre-operatively allows the cochlear implant surgeon to plan and prepare for various difficulties associated with the management of such cases. In case of a CSF gusher, a choice of an electrode with a stopper helps in effectively closing off the cochleostomy, thus reducing the chances of post-operative infections.Case description: SM, a 10-year-old girl with the diagnosis of bilateral progressive profound hearing loss showed cochlear malformations on high resolution computed tomography (HRCT) scans of the temporal bones. A detailed study and discussion with the neuro-radiologist helped in identifying the cochleo-vestibular malformations (CVM) on both sides, thus making the choice of the better ear for electrode insertion and the type of electrode. She was subjected to left ear cochlear implantation using a lateral canal labyrinthotomy approach and a Form electrode (Med El®) with a special conical stopper was used to effectively seal the labyrinthostomy.Conclusion: Common cavity (CC) and Incomplete Partition (IP) Type I present as diagnostic challenges. Getting to the right diagnosis is of paramount importance as it helps in deciding the correct ear, choosing the correct electrode, and preparing for the surgical situations the surgeon might encounter. The Form electrode shows promise due to its unique conical seal which helps in preventing CSF leakage, thus reducing the chances of post-operative infections in cases of deformed cochlea.