Sodium Fluorescein as Intraoperative Visualization Tool During Peripheral Nerve Biopsies

Area of Science:

• Neurosurgery
• Neurology
• Histopathology

Background:

• Sodium fluorescein (SF) is regaining utility in neurosurgery, particularly for brain tumor surgery.
• Peripheral nerve disorders often present with motor or sensory deficits, with magnetic resonance imaging (MRI) showing unspecific gadolinium enhancement.
• Nerve biopsies are crucial for diagnosing various nerve pathologies when MRI findings are inconclusive.

Purpose of the Study:

• To evaluate the utility of intraoperative sodium fluorescein (SF) in guiding nerve biopsies.
• To determine if SF can help identify the most affected fascicles for targeted biopsy.

Main Methods:

• A single-center study involving 5 nerve biopsies using microscope-based fluorescence with SF.
• SF was administered intravenously (1 mg/kg), followed by microsurgical dissection and fluorescence-guided fascicular biopsy.
• Image analysis compared fluorescently intense fascicles with adjacent ones, correlating findings with histopathology.

Main Results:

• All patients exhibited motor or sensory deficits, with MRI showing extensive gadolinium enhancement.
• All biopsy samples were positive, yielding diverse histopathologic results.
• Digital image analysis showed a statistically significant difference in the complementary color green (P = 0.0473) between target and adjacent fascicles.

Conclusions:

• Intraoperative SF can assist in identifying the most affected fascicles during nerve biopsies.
• This fluorescence guidance may increase diagnostic certainty in nerve biopsies for peripheral nerve disorders.
• SF offers a valuable adjunct to traditional diagnostic methods, especially when MRI findings are unspecific.