PMC8769386_01
(A-C) Right-sided internal carotid arteriogram shows a large aneurysm located at the bifurcation of the ICA and a well-developed PCOM. Lateral view, working view, and volume-rendered image of a three-dimensional angiography, respectively. The arrowheads in C indicate the anterior choroidal artery. (D) Right-sided external carotid angiogram illustrates anastomotic flow to the posterior cerebral artery from the STA. (E) Right-sided internal angiogram, lateral working view, shows the large aneurysm. PCOM from the sac is completely ligated. (F, G) MIP image obtained by high-resolution cone beam CT with diluted contrast medium shows good apposition of the flow diverter stent. The origin of the anterior choroidal artery (arrowhead) does not make contact with the stent. The arrows indicate the tip of the microcatheter (Headway 17) for coil insertion. (H) Postprocedural internal carotid arteriogram shows body filling of contrast medium to the aneurysm sac. (I) Axial slice of diffusion-weighted image obtained after intervention shows no apparent ischemic lesions. CT: computed tomography, ICA: internal carotid artery, MIP: maximum intensity projection, PCOM: posterior communicating artery, STA: superficial temporal artery.
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F1
A well-developed fetal-type PCOM originated from the aneurysm sac (Fig. 1A-1C). First, we confirmed the patient's bypass patency (Fig. 1D). After the navigation of guiding systems to the right ICA, an optimal working angle was set (Fig. 1E). The obtained reconstruction image of the maximum intensity projection (MIP) demonstrated good stent apposition (Fig. 1F). However, as illustrated by an oblique slice of the image, the anterior choroidal artery originated from the distal aneurysm neck and did not have contact with the flow diverter stent (Fig. 1G). The coil insertion was completed when the volume packing density reached about 10%, since the coil insertion was not intended for aneurysm occlusion but for the prevention of postprocedural delayed aneurysm rupture (Fig. 1H). Postprocedural MRI demonstrated no apparent ischemic lesions (Fig. 1I).
(A) Axial slice of diffusion-weighted image obtained on the seventh morning after intervention shows an acute ischemic lesion in the posterior limb of the internal capsule. (B, C) Right-sided internal carotid arteriogram, lateral view and antero-posterior view, shows complete occlusion of the aneurysm and occlusion of the anterior choroidal artery. (D) Internal carotid arteriogram after intraarterial injection of urokinase, antero-posterior view, shows recanalized anterior choroidal artery (arrowhead). (E) Axial images of CT 2 hours after procedure of intraarterial injection of urokinase show subarachnoid and intra-parenchymal hemorrhage in the frontal and parietal lobes accompanied by ventricular perforation. CT: computed tomography.
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F2
Emergent MRI revealed high signal lesion on diffusion-weighted imaging in the right posterior limb of the internal capsule (Fig. 2A). The right internal carotid arteriogram demonstrated occlusion of the anterior choroidal artery that originated from the aneurysm sac accompanied by complete occlusion of the aneurysm (O'Kelly-Marotta (OKM) grading scale D) (Figs. 2B and 2C). Recanalization of the anterior choroidal artery was achieved (Fig. 2D). The size of the hematomas was enlarged and was accompanied by an intracerebral hemorrhage, as exhibited by repeated CT (Fig. 2E).