PMC10408600_01
(a) Sagittal short T1 inversion recovery (STIR)magnetic resonance (MR) image demonstrates flow related artifact along the right lateral aspect of the spinal canal at the C5-C6 level producing a lamellated chemical shift appearance (arrow). (b) Axial volumetric T1 fat suppressed post contrast MR image at the level of the C5-C6 foramen demonstrating asymmetric extradural enhancement throughout the right C5-C6 neuroforamen and right lateral epidural space with local mass effect. Flow related artifact is also demonstrated, similar to what was seen on the sagittal STIR. (c) Axial contrast-enhanced computed tomography angiography (CTA) image at the C3-C4 level demonstrates asymmetric enhancement of the venous epidural enhancement surrounding the vertebral artery in the transverse foramen as well as along the right lateral aspect of the spinal canal (arrow). (d) Axial CTA image at the C5-C6 level demonstrates a focal extradural venous pouch, partially insinuating into the adjacent bone (arrow).
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F1
Several MRI sequences also demonstrated flow related artifact within the area of extradural enhancement [Figures 1a and b]. CT angiography (CTA) was then obtained demonstrating multilevel asymmetric venous epidural enhancement spanning C4-C6 with a focal extradural venous pouch at the C5-C6 level [Figures 1c and d].
(a) Selective catheter angiography of the deep cervical branch of the costocervical trunk. This early/mid arterial phase shows a fistulous point (arrow) leading to two large dilated venous pouches draining early to the deep cervical venous plexus (arrowhead). (b) Native oblique image at the end of treatment showing both coil and onyx cast (arrow). Notice in this mid arterial phase, the fistula and venous pouches are no longer evident.
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F2
There was a smaller contributor from the inferior thyroid branch of the thyrocervical trunk [Figure 2a]. Onyx 18 was then infused upstream of the coil and allowed to disperse throughout the fistulous network in the typical fashion of "lava flow." At the conclusion of the embolization, the fistula appears completely obliterated [Figure 2b].
(a) Axial volumetric T1 fat suppressed post contrast magnetic resonance (MR) image and (b) Sagittal short T1 inversion recovery MR image demonstrate no residual venous enhancement or mass effect. The previously visualized flow-related artifact is no longer present.
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F3
An MRI and CTA were repeated at 6-week postoperatively which demonstrated complete obliteration of the C6 AVF [Figures 3a and b].