Fluorescein-Guided Resection of Intramedullary Spinal Cord Tumors: Results from a Preliminary, Multicentric, Retrospective Study

BACKGROUND: Intramedullary spinal cord tumors (IMSCTs) are rare, heterogenous lesions that are usually enhanced on preoperative magnetic resonance imaging (MRI) because of a damaged blood-brain barrier. Sodium fluorescein is a dye that accumulates in areas of the central nervous system with a damaged BBB. Given the pattern of MRI contrast enhancement of the majority of IMSCTs, the use of this fluorescent tracer could improve tumor visualization and quality of resection. In this article, we present the first experience with the application of fluorescein-guided technique for surgical removal of IMSCTs. METHODS: Eleven patients (6 men, 5 women; mean age, 50.1 years), harboring 5 ependymomas, 3 hemangio-blastomas, 1 astrocytoma, 1 pilocytic astrocytoma, and 1 glioneuronal tumor forming rosettes were included. Sodium fluorescein (5 mg/kg) was injected immediately after patient intubation. Tumors were removed with microsurgical technique and standard neurophysiological monitoring, under YELLOW 560 filter (Pentero 900) visualization. Surgical reports were reviewed regarding usefulness and grade of fluorescein staining. Postoperative MRI was performed within 72 hours after surgery, and postoperative clinical outcome was registered. RESULTS: No adverse events were registered. Fluorescent staining was reported in 9 of 11 cases (82%), all of them enhancing on preoperative MRI (100% of ependymomas, 100% of pilocytic astrocytomas, 100% of hemangioblastomas). No fluorescence was reported in 1 astrocytoma and 1 glioneuronal tumor-forming rosette. Intraoperative fluorescence was considered helpful for tumor resection in 9 of 11 cases (82%). Gross total resection was obtained in 8 of 11 cases (72.7%). CONCLUSIONS: Our results suggest that fluorescein-guided surgery is a safe and effective technique that can be used during the surgical resection of IMSCTs presenting with contrast-enhancement on preoperative MRI.