Abstract
In this study, we report on a patient who had superior canal dehiscence and was treated by resurfacing the defect via the transmastoid approach. An 80-year-old male patient had the chief complaint of vertigo when he touched his left porus acusticus externus. As leftward nystagmus was induced by change in middle ear pressure and the existence of superior canal dehiscence was confirmed with computed tomographic scans (CT) of the temporal bones, we suspected an idiopathic labyrinthine fistula similar to the superior canal dehiscence syndrome (SCDS). At first, he was treated with medication, but as his vertigo was getting worse, he underwent surgery. A wide mastoidectomy was performed identifying the middle fossa dura. The superior semicircular canal was exposed together with the angle between the superior semicircular canal and the middle fossa bone. A bone pate was insinuated down the dehiscent canal. After the operation, no nystagmus was induced by change in the middle ear pressure and the patient did not feel any vertigo. When we anticipate the possibility of a transmastoid approach to a defect of superior canal based on preoperative CT findings, we should select this approach because the approach can avoid the more invasive middle fossa craniotomy.
