Factors affecting postoperative outcome in otosclerosis patients: Predictive role of audiological and clinical features

Abstract Objective Factors affecting postoperative hearing results of patients with otosclerosis were analyzed. Methods Included were 191 patients with otosclerosis in whom 234 primary stapes surgeries were performed from August 1991 to December 2011 by one surgeon in three tertiary hospitals. Evaluation of factors affecting postoperative hearing thresholds at individual frequencies were performed by logistic regression analysis. Results Closure of the air-bone gap (ABG) after surgery was good at 2 kHz, but poor at 4 kHz and frequencies under 1 kHz. In addition, improvement at 8 kHz was worse than that at any other frequency. Multivariate logistic regression analysis by the stepwise method showed that under the mean preoperative ABG (odds ratio [OR] = 2.42), unilaterality (OR = 2.53) and male sex (OR = 2.65) were significantly better prognostic factors at 250 Hz. At 500 Hz, under mean preoperative ABG (OR = 2.56) was the significantly better factor. No significant factors were found at 1 kHz. Cochlear otosclerosis (OR = 3.57) was a significantly worse prognostic factor at 2 kHz. Under mean preoperative ABG (OR = 2.82) and younger age (OR = 1.03) were significantly better prognostic factors at 4 kHz. At 8 kHz, worse preoperative air conduction threshold (OR = 1.96) was a significantly better prognostic factor. Conclusion Preoperative ABG, preoperative air conduction threshold, cochlear otosclerosis, male sex, laterality and age were significant prognostic factors for postoperative hearing outcome in otosclerosis patients. Especially, preoperative ABG was a significant prognostic factor at multiple frequencies. We suppose that patients with larger preoperative ABG have some other otosclerotic lesions outside the oval window niche.