case_images: PMC11090560_01
case_images: (a and b) Computed tomography (CT) showed subarachnoid hemorrhage and hydrocephalus. (c) CT angiography showed abnormal vessels around the right intracranial vertebral artery (within a circle).
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case_images: PMC11090560_01_SNI-15-149-g001.jpg
case_images: F1
case_images: A head computed tomography (CT) showed Fisher group 3 SAH and acute hydrocephalus [Figures 1a and b]. CT angiography did not reveal an arterial aneurysm, but abnormal vessels were observed around the right vertebral artery of the intracranial portion [Figure 1c], suspecting AVF.
case_images: Initial radiological images. (a) Right vertebral angiography showing an arteriovenous fistula at the craniocervical junction. (A-P arterial phase, yellow dotted circle). (b-e) Motion-sensitized driven equilibrium shows contrast effect ventral to the spinal cord (white arrow); b and d are plain, c and e are contrast-enhanced, and d and e are magnified images of b and c (within a circle). (f) Contrast spoiled gradient recalled echo at the same level of b and c did not clearly show vascular structure (white arrow).
case_images: SNI-15-149-g002.jpg
case_images: PMC11090560_01_SNI-15-149-g002.jpg
case_images: F2
case_images: No arterial aneurysm or varices was evident in the lesion [Figure 2a] at the initial cerebral angiography. Magnetic resonance image (MRI) contrast-enhanced motion-sensitized driven equilibrium (MSDE) showed a faintly enhanced area in front of the spinal cord that was presumed to be a vascular component [Figures 2b-e]. MRI contrast spoiled gradient recalled echo (SPGR) did not show any obvious vascular architecture in the same area [Figure 2f].
case_images: Changes in radiological images. (a) Day of onset; (b-e) 26 days after onset. (a and b) Three-dimensional digital subtraction angiography showed an aneurysmal structure in some of the draining veins (white circle). (c-e) Contrast spoiled gradient recalled echo also showed an aneurysmal structure (e), and the same level of motion-sensitized driven equilibrium showed an enhancing effect (c and d) white arrow (c-e).
case_images: SNI-15-149-g003.jpg
case_images: PMC11090560_01_SNI-15-149-g003.jpg
case_images: F3
case_images: A varicose structure was seen in part of the draining vein compared with initial angiography [Figures 3a and b]. MRI-enhanced MSDE [Figures 3c and d]. MRI contrast-enhanced SPGR also showed an aneurysmal structure [Figure 3e].
case_images: Intraoperative view. (a) The inside of the frame is an operation view (Three-dimensional digital subtraction angiography, white square). (b) A shunt point was noted on the cranial side of the first cervical nerve (arrow). (c and d) Double arrows indicate a draining vein. A circle indicates an aneurysmal structure.
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case_images: PMC11090560_01_SNI-15-149-g004.jpg
case_images: F4
case_images: After the dural incision, a shunt point was found at the cranial side of the first cervical nerve, which was considered to be the radicular AVF [Figures 4a and b]. Moreover, we observed the ventral side of the spinal cord, and the varices were found, so we coagulated and removed its lesion [Figures 4c and d].
case_images: Histological findings. (a) Arteriovenous fistula and aneurysmal structure (circle). (b) The aneurysmal structure was considered to be a varix because there was no internal elastic plate in the vessel wall. The vessel wall was highly thinned. (Elastica-Masson; x40). (c) The draining vein around the varix was arterialized(arrowhead). (Elastica-Masson; x10). (d) Lymphocytic infiltration and edematous changes in the wall of the draining vein surrounding the varix were observed (arrow). (Hematoxylin-Eosin; x10).
case_images: SNI-15-149-g005.jpg
case_images: PMC11090560_01_SNI-15-149-g005.jpg
case_images: F5
case_images: The lesion contained a muscular artery with an internal elastic lamina, a vein with a sparse muscular layer, and a vascular component with a thin wall that appeared to be a varices [Figure 5a]. Elastica Masson staining showed that the walls of suggested varices structures were highly thinned and lacked internal elastic lamina [Figure 5b]. The vein wall also showed irregular thickening of the muscular layer, suggesting arterialization that causes abnormal pressure load [Figure 5c]. Immunohistochemical staining results for Figure 5d is presented in Figure 6. Although there was no obvious ruptured point in the specimen, there were lymphocytic cells infiltrated around the varicose vein [Figures 5d and 6a], suggesting inflammation and hemosiderin deposition [Figure 6b], which may have occurred after bleeding.
case_images: Histological finding with immunohistochemical staining. (a) Draining vein around varix (Hematoxylin-Eosin; x40). (b) Hemosiderin deposition surrounding draining veins (Berlin blue; x40). (c) CD68-positive cells are seen in the area of hemosiderin deposition (CD68; x40). (d) MPO staining is negative (Myeloperoxidase; x40).
case_images: SNI-15-149-g006.jpg
case_images: PMC11090560_01_SNI-15-149-g006.jpg
case_images: F6
case_images: Immunohistochemical staining results for Figure 5d is presented in Figure 6. Although there was no obvious ruptured point in the specimen, there were lymphocytic cells infiltrated around the varicose vein [Figures 5d and 6a], suggesting inflammation and hemosiderin deposition [Figure 6b], which may have occurred after bleeding. CD68 staining showed positive cells around blood vessels [Figure 6c], which appeared to be macrophages. Myeloperoxidase staining was negative [Figure 6d].