PMC8769391_01
(A, B) Left vertebral angiogram shows a side wall saccular aneurysm (arrowhead), 8 x 10 mm in diameter, arising off the left V4 segment. Left PICA arises from the extracranial portion. No left AICA is apparent (A: frontal view; B: lateral view). (C, D) Contrast enhancement of vessel wall imaging MRI confirms the pseudo-lumen on the dorsolateral aspect of the aneurysm (arrow) (C: axial view; D: coronal view). Note that pathological septation can be detected in this abnormal lumen. AICA: anterior inferior cerebellar artery, MRI: magnetic resonance imaging, PICA: posterior inferior cerebellar artery.
nmccrj-8-143-g001.jpg
PMC8769391_01_nmccrj-8-143-g001.jpg
F1
Preoperative angiography and magnetic resonance imaging (MRI) including vessel wall imaging (volume isotropic turbo spin echo acquisition [VISTA]) revealed a dissecting aneurysm (8 x 10 mm) arising from the left fourth segment of the VA (Fig. 1).
Consecutive axial images of fast imaging employing steady-state acquisition MRI (3D FIESTA) in accordance with oblique-view of MRA. (A) VA which is distal of aneurysmal dome is unlikely to compress the REZ of cranial nerve VII. (B, C) VA compresses the REZ of the facial nerve at these levels (arrow). (D) Superior aspect of the aneurysmal dome is seen although facial nerve is no more detected at this level. MRA: magnetic resonance angiography, MRI: magnetic resonance imaging, REZ: root exit zone, VA: vertebral artery.
nmccrj-8-143-g002.jpg
PMC8769391_01_nmccrj-8-143-g002.jpg
F2
Rather than the aneurysm itself, the normal VA trunk just distal to the aneurysmal dome was considered likely to be compressing the REZ of the facial nerve on source images of magnetic resonance angiography (MRA) (Fig. 2). MRI at 10 months revealed no significant positional change between offending vessel and the REZ of cranial nerve VII compared with preoperative MRI (Figs. 2 and 4).
Left vertebral angiogram (left oblique view (A) and high-resolution cone-beam CT (B)) just after stent deployment. The Enterprise-2 VRD simultaneously covers the aneurysmal neck and VA compressing the REZ. (C) Schema of the postoperative view. The intracranial stent covers not only the wide neck of the aneurysm but also the responsible distal VA. (D) Final lateral image of the procedure. Contrast filling remains slightly evident in rostral aspects of the aneurysmal dome (arrowhead). Fourteen months (E) and 26 months later (F), progression of intra-aneurysmal thrombosis with minimum body filling in the vicinity of the distal neck (arrowhead) is visible on follow-up angiography. At 26 months after coil embolization, 3D rotational angiography (G) reveals the distal and proximal stent markers embedded in the opacified VA, suggesting new endothelialization (arrows). CT: computed tomography, BA: basilar artery, REZ: root exit zone, VA: vertebral artery, 3D: three-dimensional.
nmccrj-8-143-g003.jpg
PMC8769391_01_nmccrj-8-143-g003.jpg
F3
Target 360 nano coils (Stryker, Fremont, CA, USA) under general anesthesia. The stent was successfully deployed in the parent artery to cover not only the aneurysmal neck but also the distal VA trunk as the presumptively offending area (Figs. 3A-3C). Post-embolization angiography showed sufficient obliteration, but slight contrast flow remained on the rostral side of the dome (Fig. 3D). Lateral views of the left VA injection showed development of intra-aneurysmal thrombosis, but slight body filling in the distal neck remained (Figs. 3E and 3F). Three-dimensional (3D) rotational angiography at 26 months showed stent markers at both ends embedded in the VA opacification, suggesting the formation of new endothelialization on the stent surface (Fig. 3G).
Postoperative axial images of fast spin echo MRI (3D FASE) at 10 months after the endovascular treatment. There seems to be no significant positional change associated with the facial nerve and the VA. (A, D) The signal of distal VA adjacent to the aneurysm on MRA is invisible because of stent metal artifact. (B, C) VA still compresses the REZ of the facial nerve at these levels as same as Fig. 2 (arrow). MRA: magnetic resonance angiography, MRI: magnetic resonance imaging, REZ: root exit zone, VA: vertebral artery.
nmccrj-8-143-g004.jpg
PMC8769391_01_nmccrj-8-143-g004.jpg
F4
MRI at 10 months revealed no significant positional change between offending vessel and the REZ of cranial nerve VII compared with preoperative MRI (Figs. 2 and 4).