Computed Tomography Perfusion Imaging in the Selection of Acute Stroke Patients to Undergo Emergent Carotid Endarterectomy

Abstract

Severe acute stroke patients with critical carotid stenosis or occlusion without intracranial thrombus typically do not undergo emergent carotid thromboendarterectomy (CEA) because of the risk of reperfusion-related intracranial hemorrhage. Past studies have not consistently demonstrated benefit of early operative intervention. Cerebral computed tomography (CT), cervical and cerebral CT angiography (CTA), and cerebral CT perfusion (CTP) imaging may identify a subset of acute stroke patients without intracranial thrombus who may benefit from emergent CEA. Acute stroke patients underwent unenhanced brain CT imaging to exclude pathology that would contraindicate emergent therapy. Emergent CTAs of the intracranial and extracranial vessels were utilized to identify patients who presented with stroke symptoms based on the presence of isolated extracranial carotid disease in the absence of intracranial thromboembolism. CTP was then used to assess the extent of potentially reversible cerebral ischemia (penumbral tissue). Patients with isolated extracranial carotid lesions with significant reversible ischemia in the absence of large areas of irreversible cerebral damage underwent emergent CEA to salvage ischemic penumbra. In 1 year, 3 patients presented with large acute strokes in which CTA disclosed symptomatic extracranial internal carotid artery preocclusive or occlusive lesions without intracranial thromboembolic occlusions. CTP indicated a large area of ischemic penumbra with limited permanent injury. Mean age, time to presentation, and National Institutes of Health stroke score (NIHSS) were 66 years, 4.2 hr, and 19.3. All patients underwent emergent CEA with cervical carotid thrombectomy. Average time from stroke symptom onset to revascularization was 12.5 (range 5.9-19.0) hr. There were no perioperative deaths. At day 5, the mean NIHSS decreased to 7.6 and at day 30 was 4.7. The modified Rankin scale score dropped from a poststroke, preoperative level of 5 to 2.3 by day 30. Emergent CEA should be considered in patients presenting with large acute strokes based on favorable CT, CTA, and CTP findings. Emergent clot localization and physiological assessment of brain "tissue at risk" relative to irreversible cerebral infarction using CT, CTA, and CTP is now available. Utilization of this information by an experienced stroke team of neurologists, radiologists, and surgeons may aid in the recognition of a select group of patients in which emergent CEA may drive to improved outcomes.