PMC10070252_01
Computed tomography shows subarachnoid hemorrhage in the posterior cranial fossa (a). Computed tomography angiography shows abnormal blood vessels around the right vertebral artery (VA) at the C1 level (b-d). d represents an enlargement of the white dot square part of c. Right VA angiography shows an arteriovenous fistula draining into a radicular vein (e). Left VA angiography does not demonstrate vascular lesions (f). (Arrow: Right posterior inferior cerebellar artery, Thick arrow: Draining vein, Arrowhead: Shunt, Arrows: Anterior spinal artery).
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F1
Computed tomography (CT) showed massive subarachnoid hemorrhage in the posterior cranial fossa, especially around the medulla [Figure 1a]. CT angiography did not show any apparent ruptured aneurysms, although abnormal blood vessels around the right vertebral artery (VA) at the C1 level were detected [Figures 1b-d]. The right VA angiography showed an AVF at the CCJ, which was supplied mainly by the right VA and the anterior spinal artery (ASA), and it drained into a radicular vein [Figure 1e]. On the other hand, the left VA angiography did not demonstrate vascular lesions [Figure 1f].
Super-selective angiography shows that the right lateral spinal artery (LSA) originates from the right posterior inferior cerebellar artery and as a feeder (a and b). Super-selective angiography shows the occipital artery (OA) as a feeder (c and d). Super-selective angiography of both the LSA and the OA demonstrates each feeder supplying the same shunt (e and f). After embolization, right vertebral artery (VA) angiography shows residual flows from the right VA and the anterior spinal artery (ASA) (g). Left VA angiography also demonstrates the residual flow from the ASA (h). (White arrow: LSA, White arrows: ASA, White arrowhead: OA, Arrow: Posterior inferior cerebellar artery, Arrowhead: shunt, Thick arrow: Draining vein, Dot circle: Radiculomeningeal arteries from the right VA).
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F2
In detailed assessments of the vascular structures using super-selective angiography, the right lateral spinal artery (LSA) originated from the right posterior inferior cerebellar artery (PICA) and was feeding the shunt [Figures 2a and b]. Interestingly, a branch of the right occipital artery (OA) was also feeding the shunt [Figures 2c and d]. On super-selective angiography with contrast agent injections from both the LSA and the OA at the same time, the flow of each was confirmed to supply the same shunt [Figures 2e and f]. After embolization, the right VA angiography showed residual feeder flows from radiculomeningeal arteries of the right VA and spinal pial arteries of the ASA [Figure 2g]. The left VA angiography also confirmed the residual flows of the ASA [Figure 2h].
Intraoperative photographs show the posterior inferior cerebellar artery penetrating the dura mater, the lateral spinal artery (LSA) is blackened by Onyx, and the shunt is located behind the first cervical (C1) spinal nerve (a). Another intraoperative photograph from a different angle shows a draining vein at the cranial deep side of the C1 spinal nerve (b). Intraoperative indocyanine green angiography shows that the draining vein is visible in the arterial phase (c). A clip is applied to the draining vein distal to the shunt (d). (Arrow: C1 spinal nerve, Arrowhead: Posterior inferior cerebellar artery, Arrowheads: LSA blackened by Onyx, Dot circle: Location of the shunt, Thick arrow: Draining vein).
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Intraoperative photographs showed the PICA penetrating dura mater from the extradural space, and feeding arteries from the LSA were blackened by Onyx [Figure 3a]. A red draining vein was confirmed at the cranial deep side of the C1 spinal nerve [Figure 3b]. On intraoperative indocyanine green angiography, the draining vein was visible in the arterial phase [Figure 3c]. AVF at the CCJ along the C1 spinal nerve. A clip was applied to the draining vein distal to the shunt [Figure 3d].
Postoperative right vertebral artery angiography shows disappearance of the lesion (a and c: Anteriorposterior, b and d: Lateral views). (Arrow: Clip, arrowhead: Onyx).
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Postoperative cerebral angiography showed disappearance of the lesion [Figure 4].