聴力改善への技術的アプローチ

抄録

Recent advances in tympanoplasty have generally brought stable results of postoperative hearing. On the other hand, it is difficult to obtain improvement of postoperative hearing in cases of adhesive otitis media, chronic otitis media with cholesterol granuloma, or tympanosclerosis. In these special cases, the special considerations on combination of treatment is needed. Laterally located grafting at the primary stage operation and reconstruction of ossicular chain with tragal cartilage at the second stage operation are recommended for adhesive otitis media. For cholesterol granuloma otitis, combination of insertion of a ventilation tube in the eardrum and complete mastoidectomy with or without removal of the malleus head and the incus is effective as the surgical treatment.
In general, the following points are important to prevent untoword problems in the postoperative hearing in, 1) local sterilization by non-toxic material to the inner ear, 2) use of a small chisel in atticotomy for prevention of inner ear damage caused by a touch of the rotating drill to the ossicles, 3) use of “slim columella” with a diameter less than 1mm, 4) a small fenestration on the foot plate of the stapes when a columella is put on it, 5) careful measurement of bone conduction before the operation when the opposite ear is involved.