Efficay Study And Related Variance Analysis On Canal Wall Down Mastoidectomy With Tympanoplasty

[Objective]To evaluate the clinical effect and its relative factors affecting auditory results of the operation of canal wall down mastoidectomy with tympanoplasty in treating cholesteatoma and chronic otitis media with osteitis.[Methods]To follow up the 29 cases of cholesteatoma and chronic otitis media with osteitis,which underwent the operation of canal wall down mastoidectomy with one-stage tympanoplasty in the Second Hospital of Shantou University Medical College from 2008 to 2009. And then analyse their clinical material. of those 29 cases,23 cases underwent TyleⅢa tympanoplasty, another 6 cases underwent TyleⅢb tympanoplasty-Ossicular reconstruction. And 13 cases were diagnosed as cholesteatoma after operation, and other 16 cases were chronic otitis media with osteitis.[Results]29 cases were followed up 6-13 months after surgery, the rate of dry ear after operation is 97%, recrudescence of cholesteatoma is 0,2 cases of tympanic membrane reperforation.22 cases get obvious subjective hearing improvement,6 cases get no change in subjective hearing and 1 case get worse subjective hearing after surgery. The mean air bone gap(ABG) of language frequencies of 29 ears was 36.78±7.71 dB before operation, while it was elevated to 29.89±9.79 dB when beyond the six months followed up(P<0.05).There is 6.45dB improvement in ABG on average after operation.[Conclusion]The operation of canal wall down mastoidectomy with one-stage tympanoplasty for cholesteatoma and chronic otitis media can get satisfied clinical effects with a drying ear and better hearing.