Round Window Drill-Out in Advanced Otosclerosis.

OBJECTIVE

To discuss the effect of round window drill-out for otosclerosis cases with radiographic evidence of round window obliteration.

PATIENTS: Four adult patients (5 ears) were included with audiometric findings of a mixed hearing loss and radiographic evidence of otosclerosis causing round window obliteration.

INTERVENTIONS: Round window obliterative disease was addressed with a formal round window drill-out (RWD) by opening the lumen of the basal turn of the cochlea with a micro drill. The opening was then reconstructed with fascia to recreate a 2-window system.

MAIN OUTCOME MEASURES: Feasibility, Δ pure-tone air conduction thresholds, and Δ pure-tone average air-bone gap (PTA-ABG).

RESULTS

Three (60%) ears underwent primary or revision stapedectomy with RWD, 1 (20%) ear underwent delayed RWD years after stapedectomy, and 1 (20%) ear underwent RWD without stapedectomy. Median preoperative PTA-ABG was 31.3 dB. One patient (2 ears) had significant benefit with PTA-ABG improvements of 45 dB (left) and 30 dB (right). Two patients (2 ears) had a small improvement in PTA-ABG (2.5 dB, 1.3 dB), whereas 1 patient (1 ear) had worsening in PTA-ABG (2.5 dB).

CONCLUSIONS

Patients suffering from severe mixed hearing loss due to advanced otosclerosis may benefit from formal RWD to facilitate hearing aid use as an alternative to cochlear implantation.