Youichi Matsuda

Surgical treatment of labyrinthine fistula in patients with cholesteatoma

Labyrinthine fistula is one of the most common complications of chronic otitis media associated with cholesteatoma. The optimal management of labyrinthine fistula, however, remains controversial. Between 1995 and 2005, labyrinthine fistulae were detected in 31 (6 per cent) patients in our institution. The canal wall down technique was used in 27 (87 per cent) patients. The cholesteatoma matrix was completely removed in the first stage in all patients. Bone dust and/or temporalis fascia was inserted to seal the fistula in 29 (94 per cent) patients. A post-operative hearing test was undertaken in 27 patients; seven (26 per cent) patients showed improved hearing, 17 (63 per cent) showed no change and three (11 per cent) showed a deterioration. The study findings indicate that there are various treatment strategies available for cholesteatoma, and that the treatment choice should be based on such criteria as auditory and vestibular function, the surgeons ability and experience, and the location and size of the fistula.

Effect of tympanic membrane perforation on middle-ear sound transmission.

Tympanic membrane perforation causes a sound conduction disturbance, and the size of this conduction disturbance is proportional to the perforation area. However, precise evaluation of perforation size is difficult, and there are few detailed reports addressing this issue. Furthermore, such evaluation becomes more difficult for irregularly shaped perforations. This study conducted a quantitative evaluation of tympanic membrane perforations, using image analysis equipment.A significant correlation was found between the degree of sound conduction disturbance and the perforation area; this correlation was greater at low frequencies following a traumatic perforation. The conductive disturbance associated with chronic otitis media was significantly greater at low frequencies. Circular perforations caused only minor conduction disturbance. Perforations in the anteroinferior quadrant were associated with greater conduction disturbance. Traumatic spindle-shaped perforations and malleolar perforations were associated with greater conduction disturbance.