Sensorineural hearing loss after occlusion of the enlarged vestibular aqueduct

OBJECTIVE

This study aimed to report the hearing results of endolymphatic sac occlusion in patients with enlarged vestibular aqueduct syndrome.

STUDY DESIGN

The study design was a multiinstitutional retrospective case series.

SETTING

The study was conducted at tertiary otologic referral centers.

PATIENTS

The study included 10 previously unreported patients with progressive sensorineural hearing loss and vestibular aqueducts greater than 1.5 mm in diameter on computerized tomography.

INTERVENTION

Occlusion of the enlarged vestibular aqueduct was performed by means of a transmastoid surgical approach. Either intraluminal endolymphatic sac obliteration (five patients) or extraluminal extradural endolymphatic sac obliteration (five patients) was accomplished with temporalis fascia.

MAIN OUTCOME MEASURES

The postoperative pure tone average (PTA) and speech discrimination scores were compared with the preoperative levels using conventional audiometry.

RESULTS

Nine of 10 patients experienced some degree of sensorineural hearing loss. The median change in PTA was a loss of 21 decibels (dB), and 50% of the patients experienced a sensorineural hearing loss greater than 25 dB. Postoperative change in PTA ranged from +10 dB to -59 dB. The median change in speech discrimination score was a loss of 27.5%. Only one patient had an improvement in both speech discrimination score and pure tone averages after surgery. Patients who underwent extraluminal occlusion had a median PTA loss of 12 dB, and patients who underwent open sac occlusion had a median PTA loss of 34 dB. These were not statistically different.

CONCLUSION

In this series of 10 patients, 5 had a greater than 25 dB decrease in hearing after occlusion of the enlarged vestibular aqueduct. Surgical occlusion of the enlarged vestibular aqueduct showed no significant benefit in hearing preservation. The otologic surgeon is alerted to the potential for severe sensiorineural hearing loss after occlusion of the enlarged vestibular aqueduct.

Endolymphatic sac occlusion for the enlarged vestibular aqueduct syndrome

OBJECTIVE

To test the efficacy of occlusion of the enlarged vestibular aqueduct to treat the progressive sensorineural hearing loss associated with the enlarged vestibular aqueduct (EVA) syndrome.

STUDY DESIGN

Prospective controlled study.

SETTING

Tertiary care referral center.

PATIENTS

Sixteen consecutive patients (29 affected ears) with progressive sensorineural hearing loss and vestibular aqueducts >1.5 mm in diameter without other inner ear anomalies participated in this study.

INTERVENTION

In 10 patients with progressive hearing loss, the EVA was occluded in the ear with worse hearing by placing a fascia graft between the posterior fossa dura overlying the endolymphatic sac and intraosseous duct and the posterior semicircular canal without opening the endolymphatic sac. In the operative ears, serial postoperative audiograms were compared with the contralateral ear in patients with bilateral EVA and with the other nonoperated control ears.

MAIN OUTCOME MEASURES

The rate of decline of pure-tone average and speech discrimination before surgery in the operated ear was compared with the rate of decline postoperatively in the same ear. The rates of decline in the nonoperated contralateral ear from the same patient and the nonoperated control ears from other patients were also used for comparison with the postoperative rate of decline in the operated ears.

RESULTS

There was no statistically significant change in the rate of hearing loss in patients undergoing occlusion of the EVA.

CONCLUSIONS

Extraluminal soft-tissue occlusion of the EVA appears to be a safe procedure but has not yet been shown to be significantly effective in altering the sensorineural hearing loss accompanying the EVA syndrome. Further surgical intervention does not appear warranted until such time that longitudinal follow-up shows sufficient evidence of efficacy of the procedure.