# Intrathecal Fluorescein in the Surgical Management of Spontaneous Cerebrospinal Fluid Leaks: A Case Report

## TL;DR

This case report describes using intrathecal fluorescein to locate and repair a hard-to-find cerebrospinal fluid leak in a patient, showing it can be a safe and helpful tool during surgery.

## Contribution

The paper demonstrates the safe use of low-dose intrathecal fluorescein to identify and confirm repair of a spontaneous CSF leak during endoscopic surgery.

## Key findings

- Intrathecal fluorescein successfully localized a dural defect during surgery that was not clearly visible on imaging.
- The technique enabled targeted repair with no adverse effects from the fluorescein.
- Despite successful initial repair, new rhinorrhea developed, highlighting the need for close monitoring and multidisciplinary care.

## Abstract

Spontaneous cerebrospinal fluid (CSF) rhinorrhea can be difficult to localize because skull base defects may be small, multifocal, or inconspicuous on imaging. Intrathecal fluorescein has been used as an adjunct to improve intraoperative identification of CSF leaks during endoscopic repair. We report the case of a 27-year-old obese woman with a two-week history of right-sided clear rhinorrhea and orthostatic headache. Biochemical analysis of the nasal discharge was consistent with CSF. Computed tomography suggested skull base vulnerability but did not clearly identify the leak site. Low-dose, diluted intrathecal fluorescein was administered via lumbar puncture with slow injection prior to endoscopic endonasal surgery. Intraoperatively, vivid fluorescence precisely localized a dural defect at the right posterior ethmoidal roof, enabling targeted repair with a vascularized nasoseptal flap and adjunctive sealants. No fluorescein-related adverse effects occurred. While the repaired side showed no persistence, the patient developed new contralateral rhinorrhea on postoperative day one, requiring multidisciplinary reassessment and subsequent neurosurgical repair via craniotomy. Intrathecal fluorescein can be a valuable and safe adjunct (when used in low doses with appropriate dilution and slow administration) to localize radiologically occult spontaneous CSF leaks and to confirm repair integrity intraoperatively, though spontaneous leaks may be complex and warrant close surveillance and multidisciplinary management.