Advanced otosclerosis

Abstract

Otosclerosis is characterized by a continuous and aberrant process of osteolysis and osteogenesis of the endochondral bone of the otic capsule, most commonly involving the fissula ante fenestram (fenestral otosclerosis) and resulting in a conductive hearing loss. As it undergoes a maturation process, the sclerotic bone may invade deeper into the labyrinth, resulting in retrofenestral otosclerosis and gradually leading to severe mixed hearing loss and then to profound sensorineural hearing loss. This cochlear involvement of otosclerosis audiologically reflects as advanced otosclerosis (AO) and can be defined by audiometric and radiological criteria. Treatment for AO has evolved over the past 20 years with the improvement in hearing aid devices and the availability of cochlear impants (CI) as an alternative surgical option. Most authors suggest treating AO with stapes surgery and postoperative amplification by hearing aids. Cochlear implants have become available in the last 20 years and, since their introduction, many otosclerotic patients have undergone implantation with good hearing and communicative outcomes. Cochlear Implantation in otosclerosis poses some surgical problems, mainly related to cochlear obliteration and facial nerve stimulation. For cases of unsuccessful stapedotomy, the results obtained by a salvage CI are as good as those of CI when no prior stapedectomy was performed.