Acute Morphological Change in an Extracranial Carotid Artery Dissection on Transoral Carotid Ultrasonography
A 69-year-old man suddenly developed left visual field blurring, left orbital pain, and hyperesthesia of the right side of the body and was emergently admitted to our stroke center. Diffusion-weighted magnetic resonance imaging demonstrated a fresh infarct in the left post central gyrus. On emergent carotid ultrasonography, no end-diastolic flow was seen in the left internal carotid artery (ICA), which indicated occlusion of the distal part of the ICA. However, on conventional angiography performed 3 hours later, the left ICA was recanalized but was severely stenotic in the cervical portion (C2 vertebral level). To obtain detailed information about this evolving lesion, transoral carotid ultrasonography (TOCU) was performed using a color Doppler flow imaging system equipped with convex array transducers (6 MHz) that was originally designed for transrectal use. On the initial TOCU, obtained 12 hours after the stroke, double luminal change with an intimal flap, an intramural hematoma, and an oscillating thrombus were found at the C2 vertebral level of the left cervical ICA; the lumens were occluded on the color duplex image (Figure 1A and 1B and online-only Data Supplement Movie). The second TOCU obtained 16 hours after the stroke showed anterograde blood flow in both the true and false lumens (Figure 1C and 1D). An extracranial ICA dissection was diagnosed, and the patient was given intravenous heparin. The patient was followed-up with repeated TOCU examinations, and he developed no additional symptoms. The day 9 TOCU examination showed that the intramural hematoma in the false lumen had disappeared (Figure 2).
TOCU has been found to be superior to conventional carotid ultrasonography for assessing the pathological features in the far distal segment of the extracranial ICA.1,2 In particular, this unique diagnostic tool is indispensable for frequent and careful monitoring of evolving carotid diseases, including dissection.
Sources of Funding
This study was supported in part by Research Grants for Cardiovascular Diseases (18C-5) and Grants-in-Aid (H20-Junkanki-Ippan-019) from the Ministry of Health, Labor, and Welfare, Japan.
The online-only Data Supplement can be found with this article at http://circ.ahajournals.org/cgi/content/full/118/10/1064/DC1.