Epidemiologic, Imaging, Audiologic, Clinical, Surgical, and Prognostic Issues in Common Cavity Deformity: A Narrative Review.

IMPORTANCE: Common cavity deformity is a rare congenital inner ear malformation associated with profound hearing loss and attributed to an early developmental arrest of the cochlear-vestibular structures. This narrative review highlights the need to identify reliable indicators of hearing rehabilitation outcome. OBSERVATIONS: Despite its relatively simple definition, common cavity deformity varies widely in morphologic features, presence of cochlear nerve fibers and remnants of Corti organ, and outcome after cochlear or brainstem implant. CONCLUSIONS AND RELEVANCE: Cochlear implant has been shown to be a valid option for common cavity deformity, but its outcome remains variable and poor. Identification of specific neuroradiologic, audiologic, and neurophysiologic prognostic features; tailoring of the surgical approach; and standardization of outcome measures are needed to optimize the management of common cavity deformity and hearing rehabilitation after implant.