Intraoperative indocyanine green videoangiography of spinal epidural arteriovenous fistula in thoracolumbar lesions: illustrative case.

[BACKGROUND] Compared to dural arteriovenous fistulas (AVFs), the pathogenesis of extradural AVFs is unclear. Furthermore, the outcomes of surgical and endovascular treatments are inferior to those of dural AVFs, and in some cases, there are reports of poor outcomes.

[OBSERVATIONS] A 74-year-old male hemodialysis patient presented with gradually progressive gait disturbance. MRI showed high T2 signal intensity in the lower spinal cord, and angiography revealed a dural AVF. The patient was referred to the authors' hospital. Multiple small arteries were found to have refluxing veins in the dura at T12-L1 on the right side, and a diagnosis of epidural AVF was made, leading to direct surgery. During exoscopic microsurgery, the venous pouch located on the lateral ventral side was exposed, and intradural and extradural hemodynamics were confirmed using indocyanine green (ICG) videoangiograhy, followed by complete coagulated occlusion. Postoperatively, the patient's symptoms improved.

[LESSONS] There have been few cases of epidural AVF treated with exoscopic ICG videoangiography for intradural and extradural observation and healing. https://thejns.org/doi/10.3171/CASE25865.