(0935) Factors Affecting Outcomes in the Surgical Repair of Perilymphatic Fistula

Introduction: This study was undertaken to identify clinical findings and objective ancillary testing results associated with favorable surgical outcomes in the repair of perilymphatic fistulas.

Methods: A retrospective chart review was performed of all adult patients who underwent surgical repair of perilymphatic fistula from December 2017 to March 2023 at a tertiary referral center. The main outcome measures included improvement of baseline disequilibrium (BD) and episodic vertigo (EV) at 3 months after surgery and at long-term follow up (mean 16 months, range 6-48 months). Preoperative variables included etiology of PLF, symptom triggers and mitigators, audiologic results, vestibular testing results (cVEMP, ECoG, fistula test), and CT scan results.

Results: In total, 40 patients met inclusion criteria. Of them, 22 (55%) patients improved in BD at 3 months postoperatively. Preoperative symptoms triggered by pressure changes (STPC) was associated with surgical success (p = 0.038). Notably, improvement in BD at 3 months was not associated with long-term improvement. Of the total, 22 (55%) patients reported improvement in EV at 3 months postoperatively. Preoperative STPC was significantly associated with surgical success (p = 0.038). Preoperative hearing loss (HL) was also significantly associated with improvement in EV. For EV, improvement at 3 months was significantly associated with long-term improvement (p = 0.003). Etiology of PLF (traumatic vs spontaneous), objective vestibular testing results, and finding of intraoperative leak were not significantly associated with any improvement of BD or EV at 3 months or long term postoperatively.

Conclusions: Based on this study, surgery for PLF is about 50% successful regardless of etiology. A 3-month postoperative improvement in BD was not long-lasting whereas a 3-month postoperative improvement in EV was associated with long-term improvement. STPC and preoperative conductive HL were significantly associated with improvement after surgery. Notably, no other variables - even the finding of an intraoperative perilymphatic leak - were associated with surgical outcomes.