Transmastoid access in branchio-oto-renal syndrome: A reappraisal of computed tomography imaging

To evaluate for temporal bone abnormalities that might affect transmastoid surgery such as cochlear implantation in cases of branchio-oto-renal syndrome (BOR). Retrospective review. Qualitative assessment of temporal bone computed tomography imaging was performed by a neuroradiologist for 30 individuals with BOR (60 ears) and 20 controls with normal hearing (20 ears). Transmastoid access was assessed categorically across 4 features: tip development, cortex pneumatization, tegmen height, and facial recess pneumatization. The appearance of 4 standard landmarks (Koerner's septum, antrum, prominence of the horizontal semicircular canal, incudal short process) was also dichotomized as normal or abnormal. Data were compared using Fisher's exact testing. Mastoid height differed between the groups with tip underdevelopment noted in 72% of BOR ears vs. 40% of controls (p = 0.02), and a low tegmen was seen in 68% of BOR ears and 25% of controls (p