Cervical Radiculopathy Caused by Spinal Epidural Arteriovenous Fistula (SEDAVF) Without Intradural Drainage: A Case Report and Literature Review

Abstract

Spinal epidural arteriovenous fistula (SEDAVF) is a rare vascular malformation. Due to the mass effect of enlarged epidural veins and venous hypertension, progressive radiculopathy and myelopathy are likely to occur. A 33-year-old female presented with right upper extremity weakness for a month. The cause of this symptom was a SEDAVF, which was located near the C5-6-7 foramens and compressed the nerve roots. In the absence of intradural venous drainage, endovascular treatment is often difficult because of the large venous pouch. We performed endovascular trapping of the vertebral artery (VA) and loose packing of the coil material on the AVF to minimize mass effects. Immediately after embolization, the fistula was occluded, but a small new feeder vessel developed a day later. An n-butyl cyanoacrylate embolization was performed, and the fistula was successfully occluded.

Keywords: Arteriovenous fistula; Cervical spine; Therapeutic embolization.

FIGURE 1. T2-weighted cervical spine magnetic resonance shows abnormal flow void on right C5–6. (A) Abnormally dilated vessel on right C5–6 foraminal zone and extraforaminal zone is seen in sagittal T2-weighted image (arrow). (B) In axial T2-weighted image, it is observed that the abnormal vessel structure occupies the way out of the C6 nerve root (arrow).

FIGURE 2. Digital subtraction angiography of the right VA. (A) The high-flow fistula occurring directly on the right VA at the C7 lateral mass level (arrowhead) and dilated vertebral vein is observed at the C5–6 level, and this area is thought to be the main cause of the patient’s symptoms (arrow). (B) Distal flow in the right VA is poor beyond the fistula, but the brain posterior circulation is well maintained by the left VA, and small blood stilling is occurring to the right VA (arrow).

VA, vertebral artery.

FIGURE 3. (A) The distal end of the left VA was first occluded to prevent backflow of blood from the right VA. Subsequently, the proximal part of the left VA was occluded. (B) On final angiography, arteriovenous shunt flow from the right VA was completely occluded.

VA, vertebral artery.

FIGURE 4. (A) Faint minor feeding arteries from the ascending VA were observed on final angiography immediately after trapping the right VA (arrow). (B) One day after angiography, minor feeders became prominent (arrow) and the AV fistula also became more prominent compared to before (arrowhead). (C) n-butyl cyanoacrylate embolization was performed, and small feeding arteries and the AV fistula were no longer observed.

VA, vertebral artery; AV, arteriovenous.