Internal Carotid Artery Stenting for Plaque Sealing in a Patient with Non-stenotic High-Risk Plaque and Ipsilateral Embolic Cerebral Ischemia

Embolic stroke of unknown source or cryptogenic stroke accounts for a large proportion of acute ischemic strokes. Identifying possible stroke etiologies in this patient subgroup is essential for considering secondary stroke prevention strategies. The importance of non-stenotic plaques in the internal carotid artery with high-risk features (e.g., lipid-rich necrotic core or intraplaque hemorrhage) in causing ipsilateral stroke is not fully known. However, these plaques appear to be an underrecognized cause of stroke that warrants greater attention. As an adjunct to medicinal treatment, carotid artery stenting with closed-cell type stents effectively prevents ischemic strokes caused by plaque rupture or emboli in this patient subgroup. A 76-year-old man with a past medical history of arterial hypertension and peripheral atherosclerotic artery disease under treatment with aspirin and an angiotensin-converting enzyme inhibitor was admitted to our hospital’s emergency department because of a wake-up stroke with left-sided hemiparesis over 2 h. His National Institutes of Health Stroke Scale (NIHSS) score was 5 at admission, because of hemiparesis involving the left arm and leg, dysarthria, as well as sensory deficits in the left arm. Computed tomography and magnetic resonance imaging indicated multiple embolic ischemic lesions in the right precentral area and an ipsilateral non-stenotic irregular internal carotid artery plaque. The ECG and transthoracic echocardiogram findings were unremarkable. One day later, during monitoring in the acute stroke unit, the patient’s left arm became paralyzed (NIHSS 8). Non-contrast cranial CT revealed neither intracranial bleeding nor new cerebral ischemia. A loading dose of 180 mg oral ticagrelor and 500 mg intravenous acetylsalicylic acid was administered on the same day. Multiplate and VerifyNow tests revealed adequate response to the dual antiplatelet therapy. Carotid artery stenting was performed for plaque sealing in the patient under general anesthesia, without any periprocedural complications. His clinical condition after endovascular treatment was similar to that as baseline, with left arm paralysis as the main symptom (NIHSS 8, modified Rankin scale 5). The purpose of this chapter is to provide an overview of complicated non-stenotic carotid artery plaques, emphasizing diagnosis and treatment options. An endovascular approach is usually safe, suitable, and effective in preventing plaque rupture and recurrent cerebral ischemia.