Assessment of Surgical Success Rate and Acoustic Tests Findings in Patients with Otosclerosis

Otoacoustic emissions are low density sounds produced from intact cochlea measureable in the presence of an intact conduction structure. The goal of this study was to assess the surgical success rate after stapes surgery by standard audiometric tests, Distortion Product Otoacoustic Emission (DPOAE) and Transient Evoked Otoacoustic Emission (TEOAE) as methods of evaluation of postoperative hearing. A descriptive-analytic study was conducted on 50 patients with otosclerosis at Yazd Shaheed Sadoughi Medical University from March 2004 till October 2007. TEOAE, DPOAE and other behavioral audiometric tests were performed before, three months and six months after surgery on patients and results were compared. The air-bone gap threshold decreased significantly in audiogram of patients after surgery. Prior to surgery, TEOAE and DPOAE responses were not recordable in any of the patients, but after surgery, they were recordable in only two patients. Although conductive hearing loss improved significantly in patients who underwent successful stapes surgery, OAE tests were recordable in an insignificant number of patients. Therefore, this is not an optimal method for evaluating the surgical success rate.