Topical Intranasal Fluorescein: The Missing Partner in Algorithms of Cerebrospinal Fluid Fistula Detection

Objective: The aim of this work was to focus on the development and validation of the use of topical fluorescein in the intraoperative localization of cerebrospinal fluid (CSF) fistulas, and to screen its use in preoperative diagnosis of CSF rhinorrhea as well as postoperative detection of a recurrence. Materials and Methods: Twenty‐five patients with CSF rhinorrhea were treated with an endoscopic endonasal technique. Topical intranasal 5% fluorescein was used for preoperative diagnosis and intraoperative localization of the site of the leak. A change in the color of the fluorescein from yellow to green fluorescence and sometimes streaming the fluorescein over the nasal mucosa and blood denoted the presence of CSF, and the site of the leak could be traced. Results: The cause of the leak was accidental trauma in 11 patients, spontaneous in 9 patients, and iatrogenic in 5 patients. The ethmoidal roof was the most common site of leak (52%) followed by the cribriform plate (40%) and then the sphenoid sinus (8%). We have achieved 100% success rate in sealing the CSF fistulas in our 25 patients with no recurrence detected during the follow‐up period (mean, 19 ± 10 months). The preoperative use of fluorescein‐soaked cotton pledgets was 100% accurate in diagnosing CSF rhinorrhea when compared with B2 transferrin testing. The intraoperative use of topical intranasal fluorescein was also 100% accurate in locating the site of the CSF fistula when compared with the surgical findings. No major complications have been reported. Conclusion: In the presence of a clinically diagnosed CSF leakage, topical fluorescein is a very easy, sensitive, safe, and highly accurate tool in the intraoperative localization of the site and extent of CSF fistulas, and should be considered a viable noninvasive alternative to intrathecal fluorescein. We also recommend its use as a simple and quick outpatient clinic test for preoperative diagnosis of CSF rhinorrhea. It can be used postoperatively as well when there is a doubt of recurrence of the CSF leak.