Assessment of postoperative hearing in 528 middle ear and mastoid surgery cases in Tokai University Hospital.

The postoperative hearing results in cases of tympanoplasty, radical mastoidectomy, modified radical mastoidectomy and tympanoplasty combined with modified radical mastoidectomy on 528 ears, performed in the Tokai University Hospital between 1975 and 1980 were assessed. The assessment was based on pure-tone audiograms taken 3 months to 5 years after the operation. Out of 528 cases 70.5% gained better postoperative hearing, 6% showed no change of hearing and 23.5% showed deterioration of hearing. Auditory success of those who attained social hearing, air-bone gap closure to within 20dB or gained hearing of 20 dB or more was 53.4%. The results in cholesteatoma cases were poorer than those of non-cholesteatoma cases. In 44% of the cases, ossiculoplasty was performed, and the most successful ossiculoplasty results were obtained when the malleus was repositioned to the head of the stapes. Fairly good results were achieved when an artificial prosthesis, such as a Teflon-piston, Gelfoam-wire or platinum-piston, was used. The least successful results were found when the incus was transpositioned. In the non-ossiculoplasty group, type I tympanoplasty produced 59.5% auditory success whereas 37.3% auditory success was achieved in radical mastoidectomy. Better auditory success rates were obtained when the bony bridge was preserved than when it was removed. The results were identical in cases where the mastoid cavity was obliterated or when it was kept open. A new technique, "scutumplasty", was used for reconstructing the scutum. Revision surgery was required in only 3.4% of the cases.