Fluorescein sodium use during spinal ependymoma resection

Spinal ependymomas (SEs) are common adult intramedullary tumors; however, determining the absolute boundary between the tumor and the tumor residual may be difficult.We assessed outcomes following the use of fluorescein sodium (FS) during surgical removal of SEs.We performed a retrospective analysis of 112 patients with SEs who were treated at Beijing Tsinghua Changgung Hospital between December 2014 and December 2016.Each patient received intravenous FS (3-4 mg/kg) to determine the SE boundaries during surgery.Tumor removal efficiencies and tumor residuals were assessed using magnetic resonance imaging (MRI) at 10 days and 3 months after surgical recovery; McCormick's spinal function classification was also performed at the 3-month follow-up.The complete tumor removal rate was 92%(103/112).Ninetyfour patients underwent tumor removal under fluorescent light, which provided distinctive tumor fluorescence.Tumor removal under white light was performed in 18 patients; fluorescent images were invisible or indistinctive in these 18 patients.At the 3-month follow-up, sensory function (85.8%(91/106)) and movement (84.3% (86/102)) were improved in patients with pre-surgical dysfunction; urination and defecation functions were improved in 66.7%(16/24).The McCormick spinal cord functional classifications, at the 3-month follow-up, showed significant differences in the percentages of patients with disease classified to each grade (Ⅰ-Ⅳ), compared with preoperative classifications (each, P < 0.05).There was no MRI evidence of tumor relapse or residuals at the 3-month follow-up.FS use during the surgical treatment of SE enables complete tumor removal and detection of tumor residuals.