Utility of Intrathecal Fluorescein in Transmastoid Repair of Temporal Encephaloceles

To assess the safety and efficacy of intrathecal fluorescein administration during transmastoid repair of temporal lobe encephaloceles and identify predictors for intraoperative fluorescein identification.

This was a retrospective case-control study of consecutive adult patients with temporal lobe encephaloceles repaired via transmastoid approach from October 2012 to October 2024 at a single tertiary academic medical center. Medical records of qualifying patients were searched for demographics, diagnostic workup, disease characteristics, and intraoperative and postoperative outcomes. Analysis incorporated the Wilcoxon rank-sum, Pearson's X², and Fisher's exact tests, along with unadjusted Kaplan-Meier estimates. Outcomes included encephalocele recurrence and symptomatic resolution rates, fluorescein complications, and rates and predictors of intraoperative fluorescein identification.

38 patients met inclusion criteria (age 59.8 + 11.9 years, BMI 35.8 + 8.7 kg/m², 23 [60.5%] female). Recurrence (0% vs 11.5%, P = .54) and symptom resolution (83.3% vs 88.5%, P = .64) rates did not differ between patients who received and did not receive intrathecal fluorescein. No fluorescein-related complications were reported. Fluorescein was intraoperatively detected in six-twelfths cases, yielding a sensitivity of 50%. No demographic or clinical variables, including higher BMI, history of prior encephalocele, and size of largest defect, were associated with intraoperative fluorescein identification.

Intrathecal fluorescein administration preliminarily appears to be a safe adjunctive tool to identify the leak source in the transmastoid repair of temporal lobe encephaloceles, but its risk-benefit ratio remains up for debate. Higher-powered studies are necessary to explore its utility in specific circumstances and to determine which patients may benefit most.