Malleus Attachment Piston を使用した耳小骨奇形症例の検討 Surgical Treatment using a Malleus Attachment Piston in auditory ossicular malformations
We have previously reported that surgical hearing improvement was demonstrated in 88% of all ears with minor congenital malformations. However, in cases of stapes fixation with inadequate incus, only 25% were successful. Recently, we encountered 4 ears in 3 patients underwent surgery using a malleus attachment piston with auditory ossicular malformations. In this study, the condition of the ossicles, the surgical procedure, the type of malleus attachment piston (Shea Malleus Piston <SUP>®</SUP> or Schuknecht Wire Malleus Attachment Piston <SUP>®</SUP>) and the postoperative hearing results were investigated.<BR>One of the 4 ears showed absence of the footplate, deformity in the long process of the incus, and the facial nerve was inferior to the vestibule. The drilling was done superior to the facial nerve, then we connected the malleus handle and the new oval window using the all-teflon malleus attachment piston (Shea Malleus Piston <SUP>®</SUP>). Three of the 4 ears had stapes fixation and combined with the absence or deformity of the long process of the incus. Stapedotomy was performed in all of these ears and the ossicular chain using a malleus attachment piston made of wire and Teflon (Schuknecht Wire Malleus Attachment Piston <SUP>®</SUP>) or all Teflon.<BR>Hearing improvement is usually designated successful when both an air-bone gap of within 15dB and a hearing gain exceeding 15 dB are satisfied. Three of the 4 ears using a malleus attachment piston obtained successful hearing improvement.<BR>Two kinds of malleus attachment piston were usually prepared. One is made of all-Teflon, and the other is made of wire attachment and Teflon body. The advantage of the former is that postoperative extrusion is rear, but the disadvantage is that the length is short. In contrast, the latter has sufficient length and adequate angle, but it was reported that the wire was extruded through the tympanic membrane. In our last case, the wire extruded even though it was covered with connective tissue. Considering these aspects, the all-Teflon piston might be better than the wire-Teflon piston for long-term result.<BR>We showed our results of surgery with auditory ossicular malformations using a malleus attachment piston. The improvement of the hearing level in this series was relatively high compared with that of previous reports in our department. At present, we recommend the all-Teflon malleus attachment piston for the case with stapes fixation or absence with inadequate incus.
- Otology Japan
Otology Japan 16(1), 31-36, 2006-02-25
THE JAPAN OTOLOGICAL SOCIETY