Objective: Diagnosis of cerebrospinal fluid (CSF) leaks is sometimes challenging in the postoperative period following pituitary and ventral skull base surgery. Intrathecal fluorescein (ITF) may be useful in this setting.
Design: Retrospective chart review
Setting: Tertiary care center
Methods and Participants: All patients who underwent pituitary and ventral skull base surgery performed by a single rhinologist between January 2017–March 2020 were included. There were 103 patients identified. Eighteen patients received 20 ITF injections due to clinical suspicion for CSF leak during the postoperative period without florid CSF rhinorrhea on clinical exam. Computed tomography scans with new or increasing intracranial air and intra-operative findings were used to confirm CSF leaks. Clinical courses were reviewed for at least 6 months after initial concern for leak as the final determinate of CSF leak.
Main Outcome Measures: Specificity and safety of ITF
Results: Eleven (61%) ITF patients were female and 7 (39%) were male. Average patient age was 52.50±11.89. There were 6 patients with confirmed postoperative CSF leaks, 3 of whom had evaluations with ITF. ITF use resulted in 2 true positives, 1 false negative, 17 true negatives and 0 false positives. ITF sensitivity was 67%, specificity was 100%, and positive and negative predictive values were 100% and 94.4%, respectively. There were no adverse effects from ITF use.
Conclusions: Existing modalities for detecting postoperative CSF leaks suffer from suboptimal sensitivity and specificity, delayed result reporting, or limited availability. Intrathecal fluorescein represents a specific and safe test with potential utility in the postoperative setting.
Endoscopic Resection Followed by Proton Therapy With Pencil Beam Scanning for Skull Base Tumors