Abstract 1: Optical Coherence Tomography Imaging in Acute Ischemic Stroke: Preliminary Animal and Human Results

Abstract

Background: Studies evaluating endothelial injury after EVT have been done by means of retrieved human thrombus, MR vessel-wall imaging, and animal histopathologic studies. These techniques have limitations, as MR imaging has insufficient spatial resolution to directly visualize endothelium, and histopathologic examinations are ex-vivo and unable to provide real-time patterns of injury. Objective: Endovascular imaging after EVT using optical coherence tomography (OCT) to examine for vessel injury in real-time. Methodology: Three swine weighing 35-40kg were selected for the animal model. Autologous venous whole-blood was used to create thrombus. A second-generation stent retriever was used for EVT. Next, three consecutive patients with basilar artery occlusion underwent EVT and endovascular OCT imaging. Results: In the animal model, revascularization and OCT imaging was successful for all 9 vessels. Endothelial injury was observed in 4/9 (44%) of vessels, and residual thrombus was observed in 4/9 (44%) of vessels despite complete angiographic revascularization. All vessels undergoing EVT after 6 hours had evidence of endothelial injury, and 2/3 (66%) had residual thrombus. Two basilar stroke patients (2/3) 66% had significant residual thrombus despite complete angiographic revascularization. The residual thrombus was also not visible on CT angiography or MR imaging done within 24 hours of EVT. Conclusions: Endothelial injury and residual thrombus despite complete revascularization is present after EVT and can be observed in real-time using OCT. It is possible that the longer occlusive thrombus is present, the more endothelial injury will occur during EVT.