PMC8326112_01
(a) Brain CT scan obtained at the time of admission revealed subarachnoid hemorrhage in the basal cistern (Fisher group 3) and a round high-density area on the inner side of the left temporal lobe. (b) MRI showed a giant thrombosed aneurysm (largest diameter 25 mm). (c) Conventional angiography revealed that the aneurysm was located at the bifurcation of the left ICA and PcomA. The PcomA was fetal-type and originated at the saccular aneurysm neck. (d) Simple coil embolization was performed on the day after the insult. (e) Conventional angiography 1 month after simple coil embolization revealed coil migration into the aneurysmal thrombus and recanalization. ACA: Anterior cerebral artery, ICA: Internal carotid artery, PCA: Posterior cerebral artery, PcomA: Posterior communicating artery.
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F1
The World Federation of Neurosurgical Societies grade was 1; the Fisher scale was 3 [Figure 1a]. MRI and conventional angiography showed a giant thrombosed aneurysm (maximum diameter 25 mm) at the bifurcation of the left ICA and the PcomA [Figure 1b and c]. The fetal-type PcomA arose from the neck of the saccular aneurysm; the angle of the PcomA and left ICA was approximately 60  [Figure 1c]. One day after the insult he underwent simple coil embolization of the aneurysmal sac [Figure 1d]. Conventional angiography performed 1 month later showed coil migration into the aneurysmal thrombus and recanalization [Figure 1e].
(a and b) Balloon test occlusion indicated sufficient collateral flow from the contralateral ICA through the AcomA but no flow from the left VA due to the absence of the P1 segment of the left PCA. (c) Angiography after stent-assisted coil embolization indicated nearly complete occlusion and PCA patency. (d) Vaso CT revealed horizontal stenting (3.5 x 18 mm LVIS Jr. stent) from the left PCA to the left terminal ICA. (e) Follow-up angiograph obtained 2 months after the second embolization revealed coil migration into the aneurysmal thrombus and recanalization. AcomA: Anterior communicating artery, VA: Vertebral artery, PCA: Posterior cerebral artery, ICA: Internal carotid artery.
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F2
There was no flow from the left vertebral artery (VA) due to absence of the P1 segment of the left PCA [Figure 2a and b]. These procedures achieved almost complete aneurysmal occlusion; flow in the PCA was preserved [Figure 2c and d]. Follow-up angiogram obtained 2 months after the second embolization procedure revealed coil migration into the aneurysmal thrombus and recanalization [Figure 2e].
(a) Angiography after coil embolization with overlap stenting indicated complete occlusion and PCA patency. (b) Vaso CT revealed deployment of a 3.5 x 18 mm LVIS Jr. stent that overlapped the first stent. (c) The schema for overlap horizontal stenting using contralateral approach via anterior communicating artery. (d) Follow-up MRI performed 1 month after stent-assisted second coil embolization revealed no marked change in the aneurysmal size. (e) Follow-up MRI performed 1 month after the third coil embolization with overlap stenting revealed a gradual decrease in the aneurysm size (19 mm). (f) Follow-up MRI performed 6 months after the third embolization showed a further decrease in the size of the aneurysm (14 mm). ACA: Anterior cerebral artery, ICA: Internal carotid artery, PCA: Posterior cerebral artery.
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F3
After coil embolization, a 3.5 x 18 mm LVIS Jr. stent that overlapped the first stent was deployed in the same manner as the first stent [Figure 3a-c]. Although follow-up MRI performed one month after first stent-assisted coil embolization failed to show a remarkable change in the aneurysmal size [Figure 3d], follow-up MRI performed one and six months after the 2nd stent-assisted coil embolization revealed a gradual reduction in the size of the aneurysm from 19- to 14 mm [Figure 3e, f].