外耳道保存鼓室形成術後の外耳道後壁骨欠損 段階手術所見からの検討

Abstract

The incidence and location of the posterior canal wall defect were studied in 175 ears of 167 patients who underwent planned two-stage tympanoplasty by the intact canal wall technique during the last ten years. Of the 84 ears with intact scutum, the bony defect was present in 14 ears at the first operation, and in 12 of these at the second operation. Ten ears developed bony defects between the first and second operations, although the canal wall had been primarily preserved. This was ascribed to atrophy of the posterior canal wall. Of the 91 ears with destruction of the scutum, bony defects other than of the scutum were present in 12 ears at both operations. Canal wall atrophy was present in 16 of the 91 ears. Canal wall defects were listed according to Weinberg's classification. In the canal wall atrophy group, Type A lesions (a round hole in the middle of the canal wall) were seen in 20 ears; Type B lesions (a semicircular defect in the interior wall) in 3 ears; Type C lesions (a semicircular defect in the exterior wall) in 3 ears. Type D lesions (bony destruction along the entire length of the posterior wall) were not seen.