PMC7827306_01
Preoperative MR image. T2-weighted axial (a) and coronal (b) images demonstrated enlarged flow voids of the left anterior internal vertebral venous plexus (arrowheads) at C4 and C3-6. Severe compression of the nerve root and spinal cord from the enlarged epidural venous plexus is also demonstrated. The maximum intensity projection of time-of-flight images demonstrated anterior internal vertebral venous plexus at arterial phase at C2 (c) and C5 (d). The neck MR angiography showed abnormal veins around left vertebral artery (e and f).
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F1
MRI revealed an extramedullary structure, demonstrated by flow voids with abnormal vascular morphology, adjacent to the left neural foramen from C4 to C6, with compression of nerve roots and spinal cord [Figure 1]. MR angiography (MRA) [Figure 1] revealed a left VVAVF with left VA ectasia, but could not accurately identify the fistulous point.
Preoperative and postoperative digital subtraction angiography image. Anteroposterior (AP) view (a) and lateral (b) view of the left vertebral artery (VA) angiography, and oblique view (c) of reconstructed three-dimensional rotational angiography of the left VA demonstrated high-flow vertebro-vertebral arteriovenous fistula (VVAVF) between V2 segment (arrowheads) and dilated vertebral venous plexus. AP view (d) and lateral (e) view of angiogram showed that the coils (arrows) were placed in the left vertebral venous plexus just distal to the shunt, using a microballoon catheter (small arrow). The AP view (f) and lateral view (g) of the left VA angiography obtained immediately after coil embolization demonstrated the disappearance of the VVAVF.
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F2
Subsequently, the left VA digital subtraction angiography demonstrated a high-flow VVAVF connecting the left VA to the vertebral venous plexus, with a single fistulous point at the C5 level of the V2 segment [Figure 2], and large venous plexus with drainage into the anterior internal vertebral venous plexus. Tokyo, Japan). The microcatheter was gradually pulled back while placing the coils, and the fistula was firmly embolized with ED coil 10 ExtraSoft Type R 3.5 x 80 mm, 3 x 60 mm, 3 x 30 mm and 1.5 x 20 mm (Kaneka Medics, Osaka, Japan). The final angiogram from the left VA demonstrated complete disappearance of the VVAVF, with stable coils [Figure 2].
Postoperative MR image. The T2-weighted axial (a) and coronal (b) images 4 years after embolization showed reduction of flow voids of the left anterior internal vertebral venous plexus (arrowhead) at C4, and improvement of compression of nerve roots and spinal cord. The MIP images demonstrated no recurrence of the fistula at C2 (c) and C5 (d). The neck MR angiography obtained 4 years later demonstrated that the fistula was completely occluded (e).
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F3
MRI 4 years postprocedure revealed that the flow void on the left side of the spinal canal had completely disappeared and compression of C4-6 nerve roots and spinal cord released [Figure 3]. Likewise, no recurrence of the shunt was confirmed by MRA, with patency of the right VA [Figure 3e].