Congenital incudostapedial anomalies in adult stapes surgery: a case-series review

Abstract

Objectives The management of developmental anomalies of the ossicular chain and otic capsule in stapes surgery tests the otologist's diagnostic skills and flexibility in technique and prosthesis choice. We review our experience in managing various incudostapedial developmental anomalies discovered during middle ear exploration for suspected otosclerosis in adult patients. Design A retrospective case-series review was used. Setting The study was set at a military tertiary referral center. Patients and other Participants A review of 185 stapes procedures yielded 8 cases of identified congenital anomalies of the stapes or incudostapedial complex including congenital absence of the oval window with malformed incus and stapes, columellar-type stapes with promontory fixation, stapes superstructure fixation to the fallopian canal, and malformed incus with stapes superstructure fixation to the promontory. Interventions The developmental anatomy and surgical technique in each case were reviewed. The surgical technique used in each case varied depending on the specific ossicular abnormality found and whether both the stapes and incus were affected. Main outcome measures Comparison of preoperative and postoperative audiometric testing results was performed. Results All 8 ears (7 patients) that underwent a stapes procedure for either an isolated congenital stapes anomaly or a combined incudostapedial anomaly had a favorable hearing outcome, with 7 ears improving to within 10-dB and 1 ear to within 13-dB air-bone gap on postoperative audiometry. Conclusions Despite unanticipated findings of congenital anomalies of the stapes and incus during middle ear exploration for conductive hearing loss, a flexible management approach can lead to successful hearing outcomes.