(0949) Minimally Invasive Third Window Repair for Superior Canal Dehiscence: Outcomes and Long-Term Follow-Up

Introduction: Superior Semicircular Canal Dehiscence (SSCD) can cause patients to suffer from a variety of symptoms which can range from bothersome to debilitating. Trans-canal closure of the round window (RW) may represent an ideal option for initial surgical management of SSCD patients who do not desire or cannot undergo more invasive surgery.

Methods: Retrospective case series at a tertiary center of all patients that underwent primary RW closure for SSCD between 2018 – 2023. Exclusion criteria: age under 18, h/o chronic middle ear disease or fluid present on exam, prior otologic surgery. Patients were separated into one of two groups based on their BMI. Outcome measures were compared between groups, which included: the Glasgow Benefit Index (GBI), symptoms before and after surgery, and postoperative audiogram.

Results: In total, 21 ears were done in 18 patients: 6 ears in the obese group (BMI > 30) and 15 ears in the non-obese group (BMI < 30). The most common audiologic presentation was moderate mixed HL. There were no significant differences in symptomatic presentations between groups (p = 0.99), tinnitus and subjective hearing loss were the two most common complaints. Significant improvements in dizziness and aural fullness were observed, p= 0.0048 and 0.012 respectively. Of the 19 completed surveys, 10 survey scores indicated a positive change in health status. There were no significant differences in GBI Results between obese and non-obese groups (p = 0.34). The average follow-up period was 3.2 years. There were no major complications.

Conclusions: Patients should be counseled that the least likely symptom to improve is hearing loss and that there is a slight risk of high-frequency drop however this can be corrected with amplification. Trans-canal closure of the RW represents a suitable and safe option for initial surgical management in patients who do not desire or are not suitable for more invasive surgery. Significant reduction in dizziness and aural fullness is possible, and as such patients with these symptoms represent ideal candidates for a minimally invasive approach to RW closure.