PMC9168393_01
Imaging findings on admission to our hospital. (a) MRA. There are no signs of an aneurysm or other lesion. (b) T2WI. A spherical hyperintensity is evident in the right pons. (c) T1WI. No obvious signs are seen in the right pons. (d) T2*WI. The hyperintensity evident on T2WI is somewhat hyperintense, excluding the possibility of bleeding. (e) FLAIR. A spherical hyperintensity is evident in the right pons.
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F1
A spherical, space-occupying lesion appearing hyperintense on T2WI and FLAIR and isointense on T2*WI was observed in the right lateral pons [Figure 1].
Imaging before the procedure. (a)DSA Frontal view; (b) DSA lateral view; (c) 3D-RA. The arrows in (b) and (c) indicate the rostral trunk, and the arrowhead in (b) and (c) indicate the caudal trunk. Maximum diameter of the aneurysm is 8.3 mm, diameter of the aneurysm neck is 3 mm, diameter of the vessel distal to the aneurysm is 1.1 mm, and diameter of the vessel proximal to the aneurysm is 1.5 mm.
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F2
The caudal and rostral trunks of the SCA bifurcated from the aneurysm [Figure 2].
Intra-procedure cerebral angiography. (a) Intra-procedure DSA. The Headway21 is inserted and introduced into the vessel proximal to the aneurysm. (b) The caudal trunk of the superior cerebellar artery (arrowhead in (a) and (b)) is selected using the Headway21 is introduced.
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F3
After confirming the aneurysm and the course of the parent vessel, the Headway 21 was introduced into the SCA caudal trunk distal to the aneurysm, which was in the direction of progression of the Headway 21. However, selection of the SCA caudal trunk proved impossible with the GT WIRE 90  because of the curve of microwire tip is very strong, so the aneurysm was secured with a CHIKAI 0.014-inch (Asahi Intecc, Aichi, Japan) with the tip shaped into a double angle, and the Headway 21 was introduced [Figure 3]. A 3.5 mm x 17 mm LVIS was deployed from the Headway 21 so as to cover the neck of the aneurysm.
Postprocedure imaging (a) postprocedure cone-beam CT. A 3.5 x 17-mm low-profile visualized intraluminal support device (LVIS) has been deployed to cover the neck of the aneurysm without cutting off perfusion in the caudal or rostral trunk of the superior cerebellar artery. (b) Postprocedure cerebral angiography. After LVIS placement, an obvious eclipse sign is evident in the aneurysm. Sufficient flow diversion effect was considered likely to be achieved, and the procedure was concluded.
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F4
As an eclipse sign was clearly evident on confirmatory contrast enhancement, the procedure was concluded [Figure 4].
Imaging at 6 months postprocedure. (a) DSA Frontal view; (b) DSA lateral view; (c) 3D-RA. The aneurysm is completely obliterated, and assessed as O'Kelly-Marotta grading scale Grade D. Perfusion in the rostral trunk (arrow) and caudal trunk (arrowhead) of the superior cerebellar artery bifurcating from the aneurysm is preserved.
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F5
Cerebral angiography conducted 6 months after the procedure showed that perfusion in the SCA caudal trunk and rostral trunk was preserved while complete obliteration of the O'Kelly-Marotta grading scale (OKM) grade D aneurysm was observed [Figure 5].