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Updated: Aug 2, 2025

Intrathecal Application of a Fluorescent Dye for the Identification of Cerebrospinal Fluid Leaks in Cochlear Malformation
Published on: February 29, 2020
Intraoperative Visualization of Flow in Direct Cerebrospinal Fluid-Venous Fistulas Using Intrathecal Fluorescein
Levin Häni1, Amir El Rahal1, Christian Fung1
1Department of Neurosurgery, Medical Center-University of Freiburg, Freiburg im Breisgau, Germany.
Background:
Cerebrospinal fluid-venous fistulas (CVFs) are a rare cause of spontaneous intracranial hypotension. Intraoperatively, CVFs are not readily identifiable and difficult to differentiate from normal veins.
Objective:
To assess the utility of intrathecal fluorescein injection intraoperatively to visualize and identify the CVF.
Methods:
We report a case series of patients treated surgically for a CVF. After surgical exposure, we injected intrathecal fluorescein (5-10 mg) through a lumbar catheter, which we placed immediately before surgery.
Results:
Four patients with spontaneous intracranial hypotension with a suspected CVF underwent surgical ligation with adjunctive intrathecal fluorescein application. Intraoperative fluorescein injection confirmed the presence of a CVF in 3 cases. In 2 cases, we observed rapid fluorescein filling of a single epidural vein constituting the CVF. Other epidural vessels did not fill with fluorescein. In 1 case, fluorescein helped to identify a residual CVF after previous incomplete embolization. In the fourth case, no CVF was found intraoperatively. By contrast, a meningeal nerve root diverticulum was visualized, wrapped, and clipped.
Conclusion:
We demonstrate for the first time the direct intraoperative visualization of CVF using intrathecal fluorescein. CVF can be identified intraoperatively using fluorescein dye, which can be a valuable adjunct for the surgeon confronted with this disease.

