Surgery of optic-chiasmatic tumors assisted by sodium fluorescein yellow fluorescence and visual evoked potentials monitoring.

Abstract

Tumors of the anterior visual pathways are challenging to operate because of the crucial balance between extent of resection and sight preservation. Sodium fluoresceine (SF) has already been reported in maximizing brain tumor resection but not when the optic-chiasmatic region is involved. The role of Visual Evoked Potentials (VEPs) in optic-chiasmatic tumors is still debated. The simultaneous use of both technique in this setting has not been reported so far. The aim of our work is to analyse the intraoperative combination of the use of SF and VEPs in the anterior visual pathway tumor surgery. Clinical and intraoperative data from six surgical procedures on four patients affected by optic-chiasmatic tumors with preoperative visual deficits were retrospectively analyzed. In five procedures VEPs remained intraoperatively stable and no postoperative worsening of visual function was reported. In 1 case an intraoperative VEPs deterioration was predictive of a postoperative visual worsening. In all cases, tumor was fluorescent, and SF was intraoperatively helpful in guiding resection. The pattern of fluorescence was different according to the lesion histology. Based on our preliminary experience, the simultaneous combination of SF and VEPs in surgery of the optic pathway tumors seems helpful to maximize tumor resection and predict postoperative functional outcome. Since we presented a small series, larger studies are needed to confirm our data.