Optical Coherence Tomography Guided Antithrombotic Treatment After Endovascular Thrombectomy of the Posterior Circulation

Inclusion Criteria: \- All patients deemed candidates for endovascular thrombectomy(EVT) for basilar artery occlusion. As no robust guidelines exist for the role of EVT in patients with acute basilar artery occlusion, the decision for EVT is made by a team of stroke neurologist and neuro-interventionalist at our regional stroke center. Exclusion Criteria: * High-density lesion consistent with hemorrhage of any degree. * Significant established infarct size. * Contraindication to receiving post-revascularization antithrombotics for any reason (history of major hemorrhage in the past six months, hereditary or acquired bleeding diathesis, major surgery within last three months, platelets \<100 X 109 /L, coagulation factor deficiency, already on anticoagulant that would not allow administration of UFH) * Informed consent is not or cannot be obtained. * Females of childbearing potential who are known to be pregnant and/or lactating or who have positive pregnancy tests on admission. * Other serious, advanced, or terminal illness. * Patients who require hemodialysis or peritoneal dialysis. * Uncontrolled hypertension defined as systolic blood pressure\>185 mm Hg or diastolic blood pressure\>110mm Hg that cannot be controlled except with continuous parenteral antihypertensive medication