An Updated Review of Imaging Selection for Acute Stroke Reperfusion Therapy

Abstract

  Between 2014 and 2015, five pivotal stroke trials (MR CLEAN, ESCAPE, EXTEND-IA, SWIFT PRIME and REVASCAT) showed that stroke thrombectomy clearly improved functional outcome of patients with occlusion of the internal carotid artery or the M1 portion of the middle cerebral artery, with a baseline National Institutes of Health Stroke Scale score of ≥6, with a baseline Alberta Stroke Program Early Computed Tomography Score of ≥6, and who could receive thrombectomy within a 6-hour window of symptom onset. In 2018, the efficacy of stroke thrombectomy for patients with late-presenting stroke up to 16 to 24 hours of onset and who had clinical imaging mismatch or target mismatch based on RAPID analysis was also established by DAWN and DEFUSE 3 trials. “Brief imaging”-based patient selection, such as a combination of non-contrast computed tomography (CT) and CT angiography, and immediate treatment initiation are emphasized for patients within 6 hours of stroke onset. On the other hand, patient selection of a time window beyond six hours of onset necessitates “multimodal imaging” including RAPID analysis, which is unfamiliar in Japan. It will, therefore, be important how to extrapolate the evidence established on “multimodal imaging” in a real clinical setting in Japan. In addition, the establishment of precise preprocedural evaluation of occlusion site or occluded thrombi is warranted because inappropriate device selection for occlusion site, including pathological characteristics of vessel walls and thrombi, may reduce the efficacy of endovascular stroke reperfusion therapy.