PMC8769419_01
(A) Preprocedural time-of-flight MRA showed the left CCA stenosis and an extremely flexed ICA without stenosis. (B) Black-blood T1-weighted imaging demonstrated high intensity at the CCA stenosis, and the signal intensity ratio of the plaque to the sternocleidomastoid muscle indicated 2.5, suggesting high-grade vulnerable plaque. CCA: common carotid artery, ICA: internal carotid artery, MRA: magnetic resonance angiography.
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Time-of-flight magnetic resonance angiography (MRA) showed left common carotid artery (CCA) stenosis and an extremely flexed internal carotid artery (ICA) (Fig. 1A). Black-blood T1-weighted imaging demonstrated high-intensity plaque at the CCA stenosis, with a signal intensity ratio of the plaque to the sternocleidomastoid muscle of 2.5, indicating high-grade vulnerable plaque (Fig. 1B).
(A) Preprocedural left carotid angiogram, demonstrating 75% stenosis of the CCA, and showed that the ICA bends backward and turns forward in acute angulations. Intraprocedural carotid angiogram findings (B-D). (B) The wire of the occlusion balloon device is positioned along the inside curve at the edge of the stent in the ICA (arrow). (C) Under the road-mapping angiography, the balloon dilation catheter was positioned exclusively at the stenotic portion of the CCA. (D) The aspiration catheter was advanced along the occlusion balloon wire, and kept along the inside curve of the ICA, away from the dissected lesion. The arrow head indicates the tip of the aspiration catheter. (E) Carotid angiogram after stenting demonstrates favorable dilation of the carotid lumen; and the ICA, distal to the stent, shows no abnormality. ICA: internal carotid artery, CCA: common carotid artery.
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CCA stenosis and that flexed ICA was so deeply located that it was hardly detected. Carotid angiography showed 75% CCA stenosis, according to the North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria, and that the ICA was bent back at approximately 85  from the carotid bifurcation, and flexed forward at approximately 130  (Fig. 2A). Thereafter, a 10.0 mm x 40 mm carotid open-cell stent (PRESICE; Cardinal Health Japan, Tokyo, Japan) was deployed from the ICA to the CCA, fully covering the stenosis (Fig. 2B). Subsequently, a 6.0 mm x 20 mm balloon dilation catheter was positioned at the stenotic portion of the CCA and inflated for 30 seconds at 6 atm (Fig. 2C). An aspiration catheter was advanced along the occlusive balloon wire and along the inside curve of the ICA (Fig. 2D). ICA diameter due to distal occlusion balloon, favorable dilation of the carotid lumen without any abnormality and distal embolism in the cerebral circulation (Fig. 2E). In closing, after the devices were removed, the puncture site was manually compressed to perform hemostasis.
(A) Computed tomography angiography 4 days after the procedure shows 77% ICA stenosis with well-circumscribed margins and no infiltration of contrast media, at the outside curve of the ICA adjacent to the distal edge of the carotid stent. (B) Time-of-flight MRA 4 days after the procedure showed a slight hyperintensity at the ICA stenotic lesion (arrow), and the CCA was invisible due to the artifact caused by the metal stent. (C) Black-blood T1-weighted imaging showed high intensity at the ICA stenosis, suggesting an intramural hematoma (arrow head). (D) The ICA stenosis improved to 60% on computed tomography angiography 11 days after the procedure. (E) Carotid computed tomography angiography 4 months after the procedure showed improved ICA stenosis and a remarkably diminished intramural hematoma. ICA: internal carotid artery, CCA: common carotid artery.
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Computed tomography angiography 4 days after the procedure revealed ICA stenosis with well-circumscribed margins and no infiltration of contrast media, indicating 77% in the NASCET criteria, at the outside curve of the ICA adjacent to the distal edge of the carotid stent (Fig. 3A). Time-of-flight MRA showed slight hyperintensity at the ICA stenotic lesion (Fig. 3B), and the CCA was invisible due to an artifact caused by the metal stent. Black-blood MRI showed high intensity at the ICA stenosis (Fig. 3C). The carotid stenosis spontaneously improved to 60% on computed tomography angiography 11 days after the procedure (Fig. 3D). Computed tomography angiography 4 months after the procedure revealed that the ICA stenosis was additionally dilated and the intramural hematoma remarkably diminished (Fig. 3E).