Open microsurgery required to address failed endovascular embolization for a spinal dural arteriovenous fistula

Even when 3D-DSA indicates good access to a SDAVF shunt, <i>in vivo</i> penetration may be limited by root-sleeve anatomy and flow dynamics. When attempted embolization results in feeder occlusion without venous penetration, the procedure should be stopped, and early conversion to open microsurgical intervention should be considered as it is typically highly effective.