Adenovirus-Vectored COVID-19 Vaccine–Induced Immune Thrombosis of Carotid Artery

Objectives Venous thrombosis and thrombocytopenia after vaccination with the adenovirus-vectored COVID-19 vaccine ChAdOx1 nCov-19 (AstraZeneca) have been linked to serum antibodies against platelet factor 4 (PF4)-polyanion complexes. We here report vaccine-induced isolated carotid arterial thrombosis. Methods Imaging laboratory findings, treatment decisions, outcome of this case are presented. Results Eight days having received first dose vaccine, a 31-year-old man was admitted our stroke unit acute headache, aphasia, hemiparesis. D-dimers were slightly elevated, but count fibrinogen level normal. MRI-confirmed mainstem occlusion middle cerebral artery resolved within 1 hour start IV thrombolysis. A wall-adherent, nonoccluding thrombus in ipsilateral bulb identified as source embolism. Cardiac or paradoxical (venous) embolism excluded. Screening for presence heparin-induced thrombocytopenia–related positive, highly elevated IgG PF4-polyanion complexes subsequently proven. Treatment aspirin subcutaneous danaparoid, followed by phenprocoumon, led shrinkage dissolution 19 favorable clinical outcome. Discussion Vaccine history is important patients not only venous also thromboembolic events. Vaccine-induced immune brain-supplying arteries may well be handled.