Primary stapes surgery in patients with otosclerosis: prediction of postoperative outcome.

OBJECTIVES To evaluate the audiometric results of primary stapes surgery in patients with otosclerosis and to determine predictors of a postoperative air-bone gap (ABG) of 10 dB or less and a postoperative gain in air conduction (AC) exceeding 20 dB. DESIGN Retrospective cohort study. SETTING Tertiary referral center in Utrecht, the Netherlands. PATIENTS Nine hundred thirty-nine patients with otosclerosis who underwent primary stapes surgery between January 1, 1982, and March 1, 2009. INTERVENTION Primary stapes surgery. MAIN OUTCOME MEASURES Preoperative and postoperative audiometric results were compared. Logistic regression analyses were performed to evaluate which factors (ie, sex, age at surgery, bilateral otosclerosis, and preoperative 4-frequency [0.5, 1, 2, and 4 kHz] ABG, AC, or bone conduction) independently contributed to the prediction of a postoperative ABG of 10 dB or less and a postoperative gain in AC exceeding 20 dB. RESULTS A total of 72.1% of patients had a postoperative ABG of 10 dB or less, and 93.8% of patients had a postoperative ABG of 20 dB or less. Age at surgery and preoperative ABG and AC were independent prognostic determinants. A patient older than 40 years with a preoperative ABG of 30 dB or less has a 77.6% chance of achieving a postoperative ABG of 10 dB or less. A patient with a preoperative AC exceeding 50 dB and a preoperative ABG exceeding 30 dB has an 86.2% chance of achieving a postoperative gain in AC exceeding 20 dB. CONCLUSIONS Following primary stapes surgery, a postoperative ABG of 10 dB or less and a postoperative gain in AC exceeding 20 dB may be predicted with accuracies of 62.1% and 80.1%, respectively. Clinicians can use this information to inform patients more explicitly about expected postoperative audiometric results.