Simultaneous true stapes fixation and bilateral bony dehiscence between the internal carotid artery and the apex of the cochlea: the ultimate pitfall.

Background: A dehiscence of a semicircular canal can mimic the audiologic characteristics of otosclerosis.

Objective: To present a unique case report of a patient presenting with stapes fixation due to otosclerosis but persisting conductive hearing loss after uneventful laser-assisted stapedotomy with interposition of an àWengen titanium clip stapes prosthesis. Eventually, a bilateral bony dehiscence between the apical turn of the cochlea and the internal carotid artery was eventually identified, which explained the persisting postoperative conductive hearing loss. A dehiscence of the semicircular canals was duly ruled out preoperatively.

Patient: : Caucasian man aged 63 years.

Intervention: Laser-assisted stapedotomy with interposition of an àWengen titanium clip stapes prosthesis. Later on, the patient received a Bone-Anchored Hearing Aid.

Results: A 63-year-old man presented with a clinical and audiologic bilateral stapes fixation due to otosclerosis. A possible dehiscence of a semicircular canal was duly ruled out preoperatively by high-resolution computed tomographic scanning. The stapes fixation was treated lege artis by laser-assisted stapedotomy and subsequent interposition of an àWengen titanium clip stapes prosthesis, but the mixed hearing loss persisted. Eventually, a dehiscence between the apical turn of the cochlea and the internal carotid artery was identified. Thereafter, the patient was adequately helped with a Bone-Anchored Hearing Aid.

Conclusion: We think that this is the first published case of simultaneous occurrence of radiologically and preoperatively confirmed stapes fixation and bilateral bony dehiscence between the apex of the cochlea and the internal carotid artery. Preoperative imaging studies therefore should look not only for a possible dehiscence of a semicircular canal, mimicking otosclerosis, but also for a dehiscence between the cochlea and the internal carotid artery.