[A clinical study of auditory ossicular malformations in 44 ears]

Generally reporting, among the various forms of conductive hearing loss, auditory ossicular malformation clinically treated by surgery had good hearing improvement. We conducted a retrospective review of 40 patients (44 ears) with auditory ossicular malformations who were treated in our hospitals between April 2004 and March 2011. We analyzed the following preoperative features, surgical methods, and results of surgery. An otomicroscopic examination, auditory ossicules reflection, tympanometory, and temporal bone high-resolution computed tomography were undertaken in all patients. We also investigated whether these preoperative examinations would enable surgeons to make a preoperative diagnosis. There were 13 males (14 ears) and 27 females (30 ears), with an average age of 19.0 years. Classification of the pathologic condition based on surgical findings showed separation of the incus-stapes joint in 24 ears, fixation of the malleus or incus in 6 ears, fixation of the stapes footplate in 7 ears, and multifocal ossicular malformations in 7 ears. Ossicular reconstruction was performed by the modified type III method in 27 ears (including IIIc in 21 ears, IIIi-M in 1 ears, IIIi-I in 5 ears) and by the modified type IV method in 7 ears (including IVc in 5 ears, and IVi-I in 2 ears), stapes surgery in 11 ears (include total stapedectomy in 9 ears and partial stapedectomy in 2 ears) and exploratory tympanotomy in 1 ear. Postoperative hearing evaluations based on the criteria classified by the Japan Otology Society in 2010 were obtained for all cases. The procedure was deemed successful when the postoperative hearing level met at least one of these three bench marks; (1) Air-bone gap less than 15dB, (2) Recovered hearing more than 15dB, and (3) Improved or preserved hearing less than 30dB. Hearing was evaluated at 1 year after surgery. The success rates of hearing improvement was 92.3%. The success rates of postoperative hearing improvement were satisfactory. Surgeons should treat auditory ossicular malformations actively.