アブミ骨手術の長期成績

抄録

We analyzed long term result of stapes surgery patients during the period of 1993 -2004 in our hospital, and were able to follow up 81 patients of 103 ears more than lyear among them. The mean follow up period after surgery was 33 months, ranging from 12 months to 132 months. Improvement of hearing level was evaluated by the standard of the Otological Society of Japan as the improvement of hearing level. The success rate of hearing improvement were 90.8%(89/98) at lyear, 86.4%(32/37) at 95%(19/20) at 5years, and 90%(9/10) at 10 years after operation, respectively. The long term result of stapes surgery was stable.
There ware 8 ears whose post-operative hearing level worsened more than 10dB. Three ears of these 8 ears showed air-bone gap increase, of which 2 out of 3 ears increased immediastely after operation, while the one increased one year after operation. Five ears of 8 ears showed progressive sensorineural hearing loss, of which 3 out of 5 ears progressed rapidly, which might be possibly caused by surgical trauma to the inner ear during stapes surgery.
The unoperated ear which were followed-up more than 5years were 22 ears. The mean hearing level and air-bone gap at three frequency of 0.5Hz, 1kHz, and 2kHz were stable in our outpatient office within 5 years. But beyond 5 years after, the mean hearing level worsend at 125Hz and 8kHz, and the air-bone gap increased at 250Hz clearly. Because the otosclerosis patient who has conductive or mixed hearing loss unilaterally has the possibility of progressive hearing loss and/or air bone gap in unoperated ear. In the long term we should follow up as long as possible after surgery in outpatient office.