SURG-75. Fluorescein-guided microscopic confirmation of stereotactic brain biopsy specimens combined with thrombin injection reduces operative time, biopsy cores, and hemorrhagic complications

Stereotactic brain biopsy is critical for diagnosing deep or eloquent lesions, but confirmation of adequate tissue acquisition often depends on intraoperative frozen section. This can delay workflow and lead to increased numbers of samples being obtained at multiple targets if the frozen section is not definitive. We investigated whether fluorescein-guided visualization of biopsy specimens under a surgical microscope could reliably confirm diagnostic tissue in real-time. Sixteen patients underwent frameless stereotactic needle biopsy for contrast-enhancing brain lesions. Fluorescein sodium (5 mg/kg) was administered intravenously at induction. Biopsy trajectories were planned to target a contrast-enhancing portion of the lesion. After obtaining the biopsy samples, the tissue was immediately examined under a surgical microscope with a YELLOW 560 filter. The appearance of avid green fluorescence was used as a proxy for tumor presence. Initially, 8 total samples were taken in each patient. Tissue was sent for permanent pathology. To further minimize postoperative complications, a thrombin-containing hemostatic agent was injected directly through the biopsy needle at the conclusion of sampling to reduce potential biopsy-associated hemorrhage. All biopsy samples yielded diagnostic pathology of either high-grade glioma or large b-cell lymphoma. The workflow was adjusted after an intra-operative hemorrhage resulted in hemiplegia in patient 9 of 16; after that case, the number of total biopsy samples was reduced from 8 to 2-3 based on a review that all prior biopsies yielded diagnostic tissue. There were no subsequent hemorrhages. Direct fluorescein visualization of biopsy specimens provides rapid, accurate intraoperative verification of diagnostic tissue, minimizes surgical duration, and reduces the need for extensive sample numbers, thereby diminishing hemorrhagic complications. Further prospective studies with larger cohorts are warranted to validate the efficacy and safety of this integrated biopsy strategy.