Carotid Artery Stenting for Symptomatic Cortical Border Zone/Watershed Infarction Due to Severe Stenosis of the Proximal Internal Carotid Artery: Early Probably Better

Watershed (WS) or border zone infarcts involve the junction of the distal fields of two non-anastomosing arterial systems. Classic neuropathological studies describe two distinct supratentorial WS areas: (1) between the cortical territories of the anterior cerebral artery (ACA), middle cerebral artery (MCA), and posterior cerebral artery (PCA), commonly referred to as the cortical WSl; and (2) in the white matter along and slightly above the lateral ventricle, between the deep and superficial arterial systems of the MCA or between the superficial systems of the MCA and ACA, referred to as internal WS. Although the pathological and imaging characteristics of WS infarcts are well described, their pathogenesis is still controversial. Based on the well-established notion that severe systemic hypotension can cause bilateral WS infarcts, hemodynamic failure is classically considered to be the main cause of WS infarcts in internal carotid artery (ICA) disease. A 78-year-old man with a history of arterial hypertension, dyslipidemia, diabetes, ischemic heart disease, and two percutaneous coronary revascularization procedures, as well as gastroenterological and prostatic disease, presented to the emergency department (ED) with a left hemispheric transient ischemic attack (TIA) of 10 min duration 4 h before admission, with speech disturbance and numbness and weakness of the right arm. This was followed 1 h later by a small left hemisphere stroke causing right arm paresis, which was clearly evident on admission to the emergency department. The patient had experienced six episodes with similar symptoms and duration of only a few minutes during the week prior to admission, but had not sought medical attention because the symptoms were transient and always followed by complete recovery. He had thought that the symptoms were related to cervical spine disease. His National Institutes of Health Stroke Scale (NIHSS) score on admission was 2. Admission noncontrast cranial CT showed microvascular brain disease. CT angiography (CTA) showed a long, heavily calcified, irregular atherosclerotic lesion in the right ICA causing near-total occlusion. MRI diffusion weighted images (MRI-DWI) and fluid-attenuated inversion recovery (FLAIR) showed acute right hemisphere infarcts involving both the cortical WS, mainly the anterior but also the posterior watershed, and the internal WS. There were both rosary and confluent patterns. The patient received a loading dose of aspirin and clopidogrel, and the VerifyNow system was used for platelet reactivity testing. He then underwent an uneventful right ICA stent-assisted angioplasty and stenting procedure. His clinical course was unremarkable, and he was discharged within 5 days of the procedure with an NIHSS score of 0 and a modified Rankin Scale (mRS) score of 0. This chapter focuses on ischemic WS stroke caused by atherosclerosis of the large arteries and its treatment by early stent-assisted carotid revascularization.