PMC8492427_01
Magnetic resonance angiography (MRA) images of the patient. MRA obtained 6 years ago (a), 4 years ago (b), and preoperatively (c) demonstrating that the signal of the intracranial left internal carotid artery (ICA) is gradually reduced (white arrow). MRA obtained after the resection of styloid process and carotid artery stenting (CAS), demonstrated the improvement of the ICA signal (d).
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F1
Six years ago, he had a left transient amaurosis attack and magnetic resonance angiography (MRA) revealed a decreased signal of the left ICA [Figure 1a]; however, no detailed examination was performed. Although MRA showed a further decreased signal of the ICA [Figure 1b], conservative therapy with an antiplatelet was delivered for a few months since an embolic source was not detected at the origin of the ICA using carotid duplex ultrasonography examination, and he was diagnosed with idiopathic cervical ICA. Due to repeated amaurosis attacks, with the ophthalmic assessments to exclude other ocular or retinal pathology, and gradually decreasing left ICA on MRA [Figure 1c], we performed computed tomography angiography (CTA) and digital subtraction angiography (DSA). Postoperatively, he experienced no ischemic attack, and the MRA 3 months after these procedures showed improvement of the left MRA signal [Figure 1d].
CT angiography, cone-beam computed tomography (CT), and digital subtraction angiography (DSA) of the patient. Preoperative CT angiography, axial image, demonstrating that left elongated styloid process (black paired arrows) is directly impinging on the ICA (white arrow) (a). Preoperative fusion image (cone-beam CT and 3D-DSA) demonstrating the tapered and irregular stenosis of the left internal carotid artery (ICA). The tip of elongated styloid process was very close to the ICA (arrowheads), and the ICA showed severe luminal stenosis (b). Preoperative 3D-DSA (CT-like images), sagittal view, demonstrating the false lumen (white arrow) associated with the elongated styloid process (white paired arrows) (c). Fusion image (cone-beam CT and 3D-DSA) obtained after the resection of elongated styloid process demonstrated the shortening of the styloid process (arrowhead), and the tip was no longer close to the ICA (d). The ICA angiogram (lateral view) before (e) and after (f) the procedure of carotid artery stenting (CAS) demonstrated the resolution of the left ICA stenosis.
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F2
CTA demonstrated that the left elongated styloid process was directly impinged on the ICA [Figure 2a]. The DSA and cone-beam computed tomography (CT) demonstrated that the bilateral styloid process was elongated, and the left cervical ICA had an irregular lumen and stenosis with false lumen [Figure 2b and c]. Post the removal of the styloid process, no contact was verified on the image study between the styloid process and cervical ICA [Figure 2d]. In addition, the patient underwent stent placement (Stent: Precise 6 x 20) since we considered that the residual severe stenosis caused by the left cervical ICA dissection could lead to further ischemic events [Figure 2e and f].
Intraoperative photographs during resection of the elongated styloid process. Using the infradigastric muscle approach, the tip of the styloid process (*) and cervical ICA (#) is in contact with each other (a). Using the supradigastric approach, the bony structure was stripped of from its periosteum and muscle (b), and the tip that is approximately 2 cm of the process was amputated and removed (c).
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F3
In the surgery, we confirmed that the tip of the styloid process was very close to the ICA [Figure 3a], and we removed the 2 cm tip of the styloid process [Figure 3b and c].