Outcomes of transmastoid resurfacing for superior canal dehiscence using a cartilage overlay technique.

Abstract

Superior semicircular canal dehiscence is a well-described syndrome with potentially debilitating symptoms. We report on the audiologic and long-term symptom outcomes of 10 patients (12 ears) undergoing a cartilage overlay transmastoid resurfacing technique. Retrospective chart review and cross-sectional outcomes recall survey were used. A mailed questionnaire quantifying the effect of surgery on symptom severity and patient satisfaction were used. Nonlinear regression curves of pre-/postoperative air and bone pure-tone audiometric data were used to evaluate postoperative changes in hearing. Surgical failure was defined as requiring revision surgery, and rates were estimated over time using a Kaplan-Meier analysis. Most patients reported improved symptoms postoperatively and were satisfied overall with the surgical outcomes. However, four of 12 ears (33%) had a second (revision) surgery before achieving these results. Postoperatively, hearing through air and bone conduction tended to decrease at frequencies greater than 2500 Hz. The chance of avoiding a re-operation at 36 months (and up to 120 months) was estimated to be 57.1% (95% confidence interval [confidence interval]: 100%, 32.6%). The most common surgical complication was intraoperative cerebrospinal fluid (CSF) leak, encountered exclusively during dural elevation, seen in four of 12 ears (33%). Although subjectively successful at reducing symptoms, in our small sample this surgical approach did not provide a long-term stable repair and was frequently associated with intraoperative CSF leak. Offering transmastoid resurfacing to patients should involve a detailed discussion on the potential for revision surgery and risks of diminished hearing and CSF leak. 4 Laryngoscope, 129:2164-2169, 2019.