Endolymphatic sac obliteration for large vestibular aqueduct syndrome.

The objective of this study was to investigate the effects of endolymphatic sac obliteration for stabilization of progressive hearing loss in patients with the large vestibular aqueduct syndrome. This was a retrospective case review conducted at a private neurootologic office in a metropolitan area. Seven ears in six patients were subjected to surgery for obliteration of the endolymphatic sac in an effort to stabilize progressive hearing loss associated with the large vestibular aqueduct syndrome. The study population was composed of four boys and two girls 4-17 years of age. The large vestibular aqueduct was unilateral in two patients and bilateral in four patients. All seven ears demonstrated progressive sensorineural hearing loss preoperatively. Surgical tissue obliteration was performed via a transmastoid approach in seven ears. The main outcome measure was comparison of pre- and postoperative hearing levels and stability. Magnetic resonance imaging also was performed in all cases at least 6 months postoperatively to determine patency of the endolymphatic sac and vestibular aqueduct. Six of seven ears maintained stable hearing during the follow-up period, which ranged from 6 months to 6 years (mean 3.2 years). One patient showed continued progression of hearing loss postoperatively. All seven ears demonstrated continued obliteration on postoperative imaging studies. Surgical obliteration of the endolymphatic sac may stabilize hearing in patients with the large vestibular aqueduct syndrome and progressive hearing loss. These results support the theory of pressure or fluid reflux into the labyrinth as a cause of progressive hearing loss in these patients.