Superior Canal Dehiscence Surgery Outcomes Following Failed Round Window Surgery

OBJECTIVE: Round window (RW) occlusion or reinforcement is a less-invasive option compared with direct repair approaches to improve symptoms of superior canal dehiscence (SCD) syndrome. However, RW surgery is associated with variable outcomes. Middle fossa craniotomy or transmastoid repair is an option for SCD patients who fail RW surgery, but it is unknown whether sequential repair following RW plugging improves SCD symptoms or increases complications. The objective of this study is to evaluate outcomes of SCD repair via middle fossa craniotomy following failed RW surgery. STUDY DESIGN: Retrospective review. SETTING: Academic tertiary care center. PATIENTS: Adult patients with SCD syndrome who underwent failed RW surgery followed by sequential middle fossa craniotomy and plugging of the arcuate eminence defect. Patients with SCD associated with the superior petrosal sinus were excluded.None. MAIN OUTCOME MEASURE: Prospectively collected pre- and postoperative symptom questionnaires, threshold audiograms, and cervical vestibular evoked myogenic potentials (cVEMP). RESULTS: Seven SCD patients (out of a total of 194 surgical cases at our institution) underwent sequential middle-fossa SCD repair following failed RW surgery. Resolution of symptoms and reversal of diagnostic indicators were observed in the majority of subjects following sequential repair. Two of seven patients underwent a third procedure with plugging of the superior semicircular canal by a transmastoid approach due to the presence of residual symptoms. CONCLUSION: Middle fossa craniotomy and SCD occlusion is a safe and reasonable option for patients who fail RW surgery. Our cohort did not show increased risks of auditory or vestibular dysfunction.