Utility of sodium fluorescein in peripheral nerve tumor resection: a single institution experience.

Introduction: The optimal management for symptomatic or enlarging peripheral nerve schwannomas is maximal, safe resection. Sodium Fluorescein (SF) has been utilized to facilitate tumor identification and removal.

Methods: This single-institution study evaluated 17 patients with 19 tumors who underwent a microscope assisted peripheral nerve schwannoma resection with intravenous SF administration. White-light and the yellow-560 lens filter were used for microscope visualization. A grading scale was created to assess the utility of SF in differentiating tumor from normal nerve fascicles. In all patients, intraoperative neurophysiological monitoring and nerve stimulation to identify and preserve functional fascicles was utilized.

Results: Improved visualization of the tumor and normal fascicles were noted using the operating microscope with white-light. It was possible to distinguish tumor tissue from normal nerve fascicles under both white-light and the yellow-560 lens.Administration of SF imparted a distinct bright-green fluorescence to tumor tissue under the yellow-560 lens. No side effects from SF use were observed. The cost of SF was $32.64 per vial. 1 patient experienced a new motor deficit, and 1 patient developed a new sensory deficit post-operatively that did not resolve at last follow up.

Discussion: Microsurgical resection of peripheral nerve schwannomas with the use of SF and the microscope yellow-560 les may be helpful in differentiating tumor from normal healthy nerve fascicles. However, white-light illumination also allowed good visualization of the tumor and normal nerve fascicles. Intraoperative neurophysiological monitoring and nerve stimulation are indispensable to facilitate tumor resection with preservation of normal nerve fascicles.