Intraoperative indocyanine green angiography as a substitute for conventional angiography in the surgical management of spinal dural arteriovenous fistulae

Introduction Spinal dural arteriovenous fistula (dAVF) is the most common vascular malformation of the spinal cord. We performed a prospective observational study of patients with spinal dAVF who were treated by microsurgical obliteration to determine whether intraoperative indocyanine green (ICG) angiograph provides supplemental flow-related data that change the surgical plan and whether the resolution afforded by ICG angiography may substitute for conventional postoperative spinal angiography. Methods Five patients over a 6-month period were included who were treated surgically with intraoperative intravenous administration of ICG. Direct microsurgical exploration was employed to identify the intradural fistulous connection and intravenous ICG was then injected to verify the identification of the lesion. Repeat ICG angiography was performed after the fistula had been obliterated using bipolar electrocautery. All patients underwent a spinal angiogram on postoperative day 1. Results In four patients, ICG angiography correlated reliably with preoperative catheter angiography and intraoperative direct visualization. For these cases, the ICG angiogram did not alter the surgical plan, and the fistulous connection was identified and successfully treated surgically. In a fifth case, exploratory surgery for a fistula was not convincing and the information provided by intraoperative ICG angiography guided management to proceed with a cord biopsy. Conclusion ICG angiography in the setting of surgical management of spinal dAVF is a simple and effective technique for intraoperative confirmation of the relevant lesion. Postresection ICG angiography reliably demonstrated technical success and may replace formal postoperative catheter angiography. Additionally, the surgical plan may be modified based on ICG angiography.