Congenital absence of the oval window: diagnosis, surgery, and audiometric outcomes.

OBJECTIVE

To review the surgical management and outcomes of patients with congenital absence of the oval window (CAOW) undergoing the oval window drill-out (OWD) procedure.

STUDY DESIGN AND

SETTING

A retrospective chart review of patients with CAOW seen in a tertiary care otologic practice between 1991 and 2006.

PATIENTS/INTERVENTION: Patients with CAOW undergoing OWD procedure.

MAIN OUTCOME MEASURES: Findings at surgery and preoperative and postoperative audiometric outcomes (air and bone conduction thresholds; speech reception threshold).

RESULTS

Seventeen ears underwent OWD for CAOW. Four cases were aborted. For the 13 subject ears, average 1-month postoperative 4-tone air conduction and speech reception thresholds were significantly lower than preoperative thresholds. Long-term follow-up (average, 20 months) air conduction and speech reception thresholds were also significantly lower but showed a slight worsening of thresholds compared with the 1-month postoperative results. Speech discrimination scores and bone conduction thresholds remained stable.

CONCLUSION

OWD may be a viable operation for patients with CAOW, although longer follow-up is needed. Given the mixed hearing results in the current patient series, we have tempered our enthusiasm for this operation. Technically challenging, this procedure nevertheless can improve patients' hearing with minimal morbidity. Revision surgery did not result in improved outcome.