Transcranial Optical Monitoring of Cerebral Hemodynamics in Acute Stroke Patients during Mechanical Thrombectomy

INTRODUCTION: Mechanical thrombectomy is revolutionizing treatment of acute stroke due to large vessel occlusion (LVO). Unfortunately, use of the modified Thrombolysis in Cerebral Infarction score (mTICI) to characterize recanalization of the cerebral vasculature does not address microvascular perfusion of the distal parenchyma, nor provide more than a vascular “snapshot”. Thus, little is known about tissue-level hemodynamic consequences of LVO recanalization. Diffuse correlation spectroscopy (DCS) and diffuse optical spectroscopy (DOS) are promising methods for continuous, non-invasive, contrast-free transcranial monitoring of cerebral microvasculature. METHODS: Here we use a combined DCS/DOS system to monitor frontal lobe hemodynamic changes during endovascular treatment of two patients with ischemic stroke due to cervical internal carotid artery (ICA) occlusions. RESULTS AND DISCUSSION: The monitoring instrument identified a recanalization-induced increase in ipsilateral cerebral blood flow (CBF) with little or no concurrent change in contralateral CBF and extracerebral blood flow. The results suggest that diffuse optical monitoring is sensitive to intracerebral hemodynamics in patients with cervical ICA occlusion and can measure microvascular responses to mechanical thrombectomy.