PMC5364929_01
Preoperative diagnostic images in Case 1. A, B: T1-weighted magnetic resonance imaging (MRI) images, showing a double lumen in both ICAs (A, circles) suggesting dissection, and thrombus in the pseudo-lumen on the left side (B, circle). C-E: Computed tomography (CT) angiograms of the elongated styloid processes in a 3-dimensional image (C) and maximum intensity projection (MIP) images on the right side (D) and on the left side (E). The styloid processes (arrows) were quite close to the ICAs.
nmccrj-2-021-g001.jpg
PMC5364929_01_nmccrj-2-021-g001.jpg
F1
T1-weighted images showed a double lumen in both ICAs, suggesting bilateral CAD (Fig. 1A). Thrombus was observed in the pseudo-lumen on the left side (Fig. 1B). CAD (Fig. 1C-E). Cerebral angiography confirmed bilateral ICA dissection.
Postoperative images of Case 1 after surgical resection of the styloid process and carotid artery stenting. A, B: Computed tomography (CT) angiogram images after the resection of the styloid process. Detachment of the styloid process from internal carotid artery (ICA) was confirmed. Intimal flap in the right ICA was observed (B, arrow). C, D: Right common carotid artery angiogram before (C) and after (D) stent placement. After stent placement, the stenosis in the true lumen has been improved.
nmccrj-2-021-g002.jpg
PMC5364929_01_nmccrj-2-021-g002.jpg
F2
The styloid process was exposed and then drilled and removed (Fig. 2A, B). The intimal flap and the pseudo-lumen were covered by the stent, and the stenosis of the true lumen was remarkably improved (Fig. 2C, D).
PMC5364929_02
A: Right internal carotid artery angiogram in Case 2 just after recanalization, showing irregular stenosis in the internal carotid artery (ICA). The position of the styloid process is shown with dotted lines. B: The stent was deployed to cover the dissection. C: Right common carotid artery angiogram after stent placement, showing complete restoration of the true-lumen. D: Computed tomography (CT) angiogram after stenting. The styloid process (arrow) was adjacent to the stented ICA.
nmccrj-2-021-g003.jpg
PMC5364929_02_nmccrj-2-021-g003.jpg
F3
Although early recanalization was obtained using a Merci Retriever, there was remaining irregular stenosis in the recanalized ICA, which suggested preexisting cervical artery dissection (Fig. 3A). A stent (Johnson & Johnson) was carefully deployed to cover the dissection, after administration of dual antiplatelet therapy (clopidogrel and aspirin) (Fig. 3B, C). CTA performed on the next day showed that the elongated styloid process (34.3 mm in length) was in contact with the dissected part of the right carotid artery (Fig. 3D).
PMC5364929_03
A: Preoperative computed tomography (CT) angiogram in Case 3, showing elongation of the left styloid process. B: The left styloid process (arrow) was adjacent to the internal carotid artery (ICA), causing dissection and aneurysmal change.
nmccrj-2-021-g004.jpg
PMC5364929_03_nmccrj-2-021-g004.jpg
F4
CTA showed elongation of both styloid processes (42.4 mm on the right side and 45.9 mm on the left side) and an aneurysm of the left cervical ICA (Fig. 4).