PMC9990775_01
(a) Axial computed tomography (CT) on the initial visit shows diffuse subarachnoid hemorrhage distributed mainly at the interhemispheric fissure. (b) CT angiography shows an azygos anterior cerebral artery (ACA) with hypoplasia of the A1 segment of the right ACA. (c) Three-dimensional rotational angiography (3D-RA) with injection from the left internal carotid artery shows a tiny bulge on the distal bifurcation of an ACA on day 0. This small aneurysm rides from the distal end of the azygos trunk to the left pericallosal artery. (d) The follow-up 3D-RA on day 4 shows obvious enlargement of the aneurysm.
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F1
The thickest hematoma of the SAH was noted in the interhemispheric fissure on computed tomography (CT) [Figure 1a]. CT angiography and digital subtraction angiography (DSA) showed an azygos ACA with hypoplasia of the A1 segment of the right ACA [Figure 1b]. This small aneurysm was arising from the distal end of the azygos trunk to the left pericallosal artery [Figure 1c]. DSA after waiting for 4 days under sedation showed obvious enlargement of the aneurysm [Figure 1d].
Stent-assisted coiling was subsequently performed on the same day as the follow-up digital subtraction angiography (DSA). (a) Left carotid angiography at a working angle shows a blister-like aneurysm (BLA) (black arrow) at the distal bifurcation of the azygos trunk and a Headway 17 microcatheter placed on the left pericallosal artery for stenting. (b) The fluoroscopic image demonstrates two loops of a single GalaxyG3 coil inside the BLA (black arrow) and the implanted LVIS junior stent from the left pericallosal artery to the azygos trunk (long thin black arrow). (c and d) The final DSA shows immediate complete occlusion of the BLA (black arrow) and thrombus at the origin of a right pericallosal artery (black arrowhead).
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F2
Tactics (Technocrat, Aichi, Japan) placed on the A1 segment of the left ACA as an intermediate catheter [Figure 2a]. An Excelsior SL-10 (Stryker Neurovascular, Kalamazoo, MI, USA) shaped by steam on a 45-degree curve was placed in the proximal part of the aneurysm using a Traxcess 0.30-mm (0.012-inch) microwire (Microvention) because of the difficulty of placing the microcatheter inside the aneurysm. After a 2.5-mm * 17-mm low-profile visualized intraluminal support (LVIS) Jr (Microvention) was deployed to just the distal neck of the aneurysm, a Galaxy G3 mini 1-mm * 20-mm (Cerenovus, Irvine CA, USA) was poured into the aneurysm. Two loops of the coil were placed inside the aneurysm by the microcatheter placed in the proximal of the aneurysm, which moved gradually with the coil protruding from the tip. The half-deployed stent was placed across the neck of the aneurysm to the end [Figure 2b]. Final postembolization DSA showed that the contrast effect of the aneurysm disappeared [Figure 2c]. Because a thrombus was found at the origin of the right pericallosal artery [Figure 2d], the patient was administered 80 mg of ozagrel sodium, and no blood vessels occluded.
Magnetic resonance imaging-diffusion-weighted imaging shows multiple spotty high intensities in the bilateral anterior cerebral artery region.
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F3
No new postoperative neurological deficits were found, and magnetic resonance imaging-diffusion-weighted imaging showed multiple spotty high intensities in the ACA region bilaterally [Figure 3], and magnetic resonance angiography showed no vessel occlusion.
The follow-up digital subtraction angiography (DSA). (a and b) The DSA 14 (a) and 30 (b) days after onset shows the residual contrast effect and gradual thrombosis within the dome of a blister-like aneurysm (black arrow in (a) and (b)). (c) The DSA at 90 days shows complete obliteration (black arrow).
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F4
However, the findings showed stagnation of contrast in the venous phase and did not show contrast along the aneurysm wall, so follow-up was continued [Figure 4a]. Follow-up DSA 30 and 90 days after onset showed that the aneurysm thrombosed gradually and reached complete occlusion 90 days later [Figures 4b and c].