In Asia, otosclerosis is not so common as in Europe and North America. The reports about stapes surgery is not many in Japan. So we report the hearing results in stapes surgery performed in our institution.
We analyzed the hearing results of 101 ears which were performed stapes surgery at Osaka University Hospital from April 2007 to December 2014. We evaluated the hearing results by criteria of AAO-HNS at 6 months after surgery and at 2 years after surgery. Furthermore, we analyzed hearing gain, air-bone gap and air conduction threshold by each frequency.
Small fenestration stapedotomy was performed in 63 ears. Partial stapedectomy was performed in 23 ears and total stapedectomy was performed in 12 ears. The CO2 lazer was used to fenestrate the foot plate of stapes in 40 ears. The manual perforator was used in 56 ears. The details of prostheses are as follows: Teflon wire piston; 64 ears, Teflon piston; 20 ears and titanium clip piston; 14 ears. The total success rate (i.e. the air-bone gap is smaller than 10 dB) is 70%. Concerning the success rate by A-B gap (AAO-HNS criteria), there was no statistical difference in fenestration methods, fenestration devices or prostheses. To see by each frequency, the hearing gains at high frequencies (2k, 3k and 4k) are better in stapedotomy than in stapedectomy at 6 months after surgery. But there is no significant difference at 2 years after surgery. The air conduction threshold at high frequencies in stapedotomy at 2 years after surgery worsened than at 6 months after surgery.
The hearing results are substantially equal to other reports. The A-B gap after surgery does not depend on either fenestration methods, fenestration devices or prostheses in our report. The reason why the air conduction threshold at high frequencies in stapedotomy worsened at 2 years after surgery seems re-calcification around the piston.