Surgical Management for Dysplastic or Congenitally Absent Oval Window

To evaluate surgical findings and hearing results for patient's undergoing the described surgical approach for congenitally absent or dysplastic oval window (OW).

The Institutional Review Board approved retrospective review of patients with conductive hearing loss (CHL) operated on from 1992 to 2016.

Academic tertiary center.

Patients with CHL, an intact tympanic membrane (TM), and without history of chronic infection underwent middle ear exploration. Eleven patients and 13 ears underwent an oval window drill-out (OWD) procedure.

Eleven patients presented, all with dysplastic or congenitally absent oval window (CAOW). CHL was identified using audiometry and tuning forks, many patients also had preoperative computed tomography temporal bones. A transcanal approach was used and an OWD was performed with a variety of prostheses placed.

Audiometric studies before and after intervention were compared with 12 month and long-term follow-up (1-22 yr).

Preoperative air-bone gaps ranged from 40 to 60 dB and averaged 55.1 dB. Postoperative air-bone gaps ranged from 0 to 60 dB and averaged 24.1 dB. The preoperative pure-tone average (PTA) ranged from 55 to 99 dB and averaged 71.3 dB. Postoperative PTA ranged from 21 to 108 dB and averaged 49.6 dB.

Dysplastic and CAOW are uncommon congenital major ear anomalies. OWD is a viable treatment option, though careful counseling is critical, as significant complications are possible, especially with facial nerve (FN) abnormalities. This series demonstrates successful closure of the air-bone gap for many patients with this technique.