Round window atresia – a case report

Summary Only a few cases of a round windows atresia have been reported in the literature so far. The dia gnosis is based on the preoperative CT scan and local fi ndings during a middle ear exploration. The complete round window closure leads to a signifi cant conductive hearing loss. The hearing test result might be similar to the one found in otosclerosis. We report a case of 30-year-old woman, who previously underwent three surgeries for suspected otosclerosis without any hearing improvement. A round window atresia was only identified during following revision surgery, as well as a missing stapedial muscle, an abnormal shape and movement of the stapes footplate. In order to achieve a functional inner ear hydrodynamics, a cochlear fenestration was performed. Although there was a signifi cant improvement in the cochlear reserve at speech frequencies after the operation, the patient didn’t report any hearing improvement. Although otosclerosis may be considered as a cause of the conductive hearing loss preoperatively, rare dia gnoses should not be neglected. The aim of this case report is to share the experience and highlight mistakes made. After each unsuccessful stapedoplasty with unsatisfying hearing gain, a high resolution CT should be performed to exclude third window syndrome or another rare abnormality. Key words atresia – cochlear fenestration – round window – stapes surgery