Fluorescence Imaging With Indocyanine Green(ICG) in Endoscopic Spinal Surgery

With the accelerated pace of the global aging society, the prevalence of degenerative diseases is increasing. At present, spinal degenerative diseases caused by body degeneration have become the most common type. With the continuous deepening of the research on spinal degenerative diseases and the continuous development, update and promotion of minimally invasive surgery technology and instruments, minimally invasive surgery has attracted more and more attention of spine surgeons due to its advantages of rapid recovery, small trauma and fewer complications. The core of endoscopic spinal surgery is nerve root decompression. The procedure is centered on the nerve roots, which can be damaged with the slightest carelessness. According to statistics, the incidence of nerve root injury under spinal endoscope is 1.8-2.5%. Most of the injuries include the stimulation and edema of the nerve root during the operation, which may lead to postoperative sensory retardation and motor weakness, which will damage the patient's physical function and reduce overall satisfaction. The intraoperative nerve exploration is time-consuming and critical, and the variability of the patient's nerve anatomy will also add difficulties to the operation. A real-time auxiliary intraoperative nerve identification technology is necessary. With the progress of optical technology, fluorescent-guided surgery has shown considerable prospects in assisting in identifying nerves. Indocyanine green (ICG) is the only fluorophore approved by the US Food and Drug Administration (FDA) for intraoperative near-infrared imaging. It can emit near-infrared light after being irradiated by excitation light, which has the characteristics of high penetration depth, low spontaneous fluorescence and high sensitivity. At present, ICG near-infrared fluorescence imaging has been applied to tumor detection, lymphangiography and vascular perfusion evaluation. In recent years, more and more researchers have paid attention to the application value of ICG fluorescence imaging in neuroimaging. It has been applied to clinical research of thoracic sympathetic ganglion, facial nerve, phrenic nerve and pelvic nerve.