Yellow 560 Microscope for Intraoperative Visualization of Fluorescein Stained Intracranial Lesions

This study focuses on implementing Yellow 560 for the direct intraoperative visualization of Fluorescein Sodium stained intracranial lesions to facilitate extend of surgery, develop better treatment protocols, and improve the prognosis of a wide array of neurosurgical diseases. More specifically, for the patients who are undergoing surgical intervention for the treatment of their brain aneurysm, tumor, arteriovenous malformation or fistula, the investigators will inject the dye intraoperatively to assess for residual aneurysm, tumor or in general residual lesion which must be corrected.