Two Cases of Malleostapedotomy in Congenital Oval Window Atresia
A 40-year-old male visited our outpatient clinic with right-sided hearing loss since childhood. The patient had no previous history of trauma, and showed conductive hearing loss with an air-bone gap (ABG) of 50 dB (60/10 dB; ). Temporal bone computed tomography (TBCT) showed normal images of the malleus, but revealed atresia of the right-side oval window, with abnormal placement of the facial nerve (). First, ossiculoplasty using a total ossicular replacement prosthesis (TORP) was performed, with no hearing improvement. We then planned a second operation, a malleostapedotomy. The tympanic cavity was exposed through an endaural approach and the posterior wall of the external auditory canal was leveled down with a mallet and gauge to expose the stapes. During the operation, a normal structure of the malleus was noted, but the long process of the incus was short. Additionally, the stapes was missing, and the facial nerve was covering the oval window. The facial nerve was displaced towards the cephalic side using a fine swab, and a 0.6-mm window was drilled in the obstructed oval window using a 0.4-mm Skeeter drill. The facial nerve was then put back in the original position. Because the malleus was placed anterior to the stapes footplate, the piston wire prosthesis was bent 20°, modified to a 7-mm length, and fixed on the normal malleus (). At 1 year following the operation, pure tone audiometry showed improvement of the ABG, from 50 to 30 dB (), with no complication of facial nerve palsy or dizziness.