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 progres sive sensorineural hearing loss and vestibular aqueducts greater than 1.5 m m in diameter on computerized tomography. Intervention: Occlusion of the enlarged vestibular aqueduct was performed b y means of a transmastoid surgical approach. Either intraluminal endolympha tic sac obliteration (five patients) or extraluminal extradural endolymphat ic 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 con ventional audiometry. Results: Nine of 10 patients experienced some degree of sensorineural heari ng loss. The median change in PTA was a loss of 21 decibels (dB), and 50% o f the patients experienced a sensorineural hearing loss greater than 25 dB. Postoperative change in PTA ranged from +10 dB to -59 dB. The median chang e 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 a fter surgery. Patients who underwent extraluminal occlusion had a median PT A loss of 12 dB, and patients who underwent open snc 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 decre ase in hearing after occlusion of the enlarged vestibular aqueduct. Surgica l occlusion of the enlarged vestibular aqueduct showed no significant benef it in hearing preservation The otologic surgeon is alerted to the potential for severe sensiorineural hearing loss after occlusion of the enlarged ves tibular aqueduct.