[Bifenestration--a hearing-improving operation in severe ear malformations]

Round window atresia in association with congenital stapes fixation

OBJECTIVE

To document an association of round window atresia with congenital stapes fixation, discuss the diagnostic role of computed tomography, and implicate the clinical significance of these anomalies.

STUDY DESIGN

Retrospective chart review and review of the literature.

RESULTS

The authors report three pediatric cases of round window atresia. All cases presented with hearing loss of a conductive nature (two cases bilateral, one unilateral). Two patients underwent middle ear exploration, demonstrating stapes fixation and the absence of a round window. Stapedectomy was performed in both cases without postoperative hearing improvement. Subsequent revision stapedectomy was also unsuccessful in one of these cases. The unoperated case represents the fraternal twin of one patient. In all cases, computed tomography scanning demonstrated findings consistent with atresia of the round window niche without cochlear anomaly.

CONCLUSIONS

An association of round window atresia and congenital stapes fixation is apparent. The mechanism of the conductive hearing loss following stapedectomy remains poorly understood. Computed tomography imaging and surgical confirmation are probably both necessary to establish the diagnosis of round window atresia.