Hearing Outcome after Canal Wall down Mastoidectomy and Wullstein Type III Tympanoplasty

Objective: This is to report the hearing outcome in patients who had CSOM, with ossicular erosion, treated with Canal Wall – Down Tympanomastoidectomy and the classical Wullstein type III tympanoplasty (CWDT) in which the graft was applied directly on the stapes footplate.
Methods: This was a retrospective review of record charts of patients' hearing status before surgery and between 18 – 24 months after surgery using the pure tone average derived according to the guidelines of the Committee on Hearing and Equilibrium of the American Academy of Otolaryngology Head and Neck Surgery (AAO-HNS). All the patients had audiometry done with a computer audiometer BA 20 Kamplex in a sound - proof (acoustic) booth. Calibration: SO/DP 389 – 1983.
Result: CWDT was done in 21 patients, 13 females and 8 males, aged 5 - 64 years, mean 30(SD = 15.59). All the patients had CSOM with mastoid abscess and partial or complete erosion of the malleus and incus and intact footplate of the stapes. Additional findings included foreign body in the middle ear 2, polyp 6 and meningitis 3. The duration of CSOM was 3 – 35 years, mean 17.5(SD = 8.9) and there was correlation with pre-operative air conduction (AC) (r =0.580, P = 0.006) and preoperative air- bone gap (r = 0.610, P = 0.003). The mean hearing gain was 5dB (with a range between - 5 and 25dB), and hearing gain between 10 – 25dB was achieved in 5/21(24%). The pre-operative AC was 30 – 60dB, mean 45dB (SD = 9.08) and bone conduction (BC) was 10 - 30dB, mean 20.7 dB (SD = 4.55). While the postoperative AC was between 25 and 55dB, mean of 39.29(SD = 9.5), the BC was 15 - 35dB, mean 20.23(SD = 4.9). The preoperative air – bone gap was 10 – 40 dB, mean 24.29(SD = 8.8) while post-surgery it was 10 – 35 dB, mean 19.29(SD = 7.8).
Conclusion: Hearing benefit from CWDT is minimal, a second look surgery and ossiculoplasty, bone – anchored hearing aid or a hearing aid may be expedient for further hearing augmentation.