Technique and Expected Benefit of Intraoperative Perfusion Imaging of Peripheral Nerves

Peripheral nerve surgery, particularly in cases of nerve compression syndrome (NCS), necessitates a comprehensive evaluation of intraneural blood flow, as localized reductions in nerve perfusion are integral to the etiopathogenesis of such conditions. Although nerve perfusion is currently guided by morphologic characteristics, this assessment is subjective and prone to bias. Intraoperative fluorescence-assisted perfusion imaging with indocyanine green (ICG) is an established tool in flap and lymphatic surgery to objectively assess perfusion intraoperatively. However, only a few unspecific applications of ICG in peripheral nerve surgery have been published so far. In this study, we performed intraoperative perfusion imaging using ICG in 16 consecutive operations within the peripheral nervous system, including microsurgical reconstructions after obstetric brachial plexus injury, decompression for NCS, and vascularized ulnar nerve interposition transfers. Our findings show the utility of ICG in delineating healthy perfusion borders at proximal and distal stump levels after neuroma resection, and we demonstrate a correlation between histological findings and these clinically observed perfusion patterns. In NCS cases, we demonstrate that ICG imaging is effective in highlighting reduced perfusion predecompression and improved perfusion postdecompression. Additionally, ICG proved valuable for assessing perfusion of free vascularized nerve grafts. Intraoperative ICG perfusion imaging is a valuable tool during surgery of the peripheral nervous system, providing insights into the etiopathogenesis of NCS and aiding in the visualization of perfusion. This study underscores the potential of ICG in nerve surgery and its applicability for improving surgical outcomes and advancing our understanding of peripheral nerve pathologies.