{Reference Type}: Case Reports {Title}: Fatal hyperacute left main thrombosis after aortic root surgery. {Author}: Zivkovic I;Milacic P;Tabakovic Z;Micovic S;Milicic M; {Journal}: Turk Gogus Kalp Damar Cerrahisi Derg {Volume}: 32 {Issue}: 2 {Year}: 2024 Apr {Factor}: 0.704 {DOI}: 10.5606/tgkdc.dergisi.2024.24507 {Abstract}: Acute aortic root thrombosis is a potentially lethal condition due to the possibility of thrombosis into the ascending aorta branches, resulting in various clinical manifestations. A 29-year-old male patient was admitted to our center with hyperacute left main thrombosis after elective Bentall procedure. Due to massive left ventricular infarction, the patient was supported by extracorporeal membrane oxygenation, but without success to recovery. The patient's blood analyses revealed a high level of the Factor VIII. In conclusion, Factor VIII levels in the blood are elevated by genetic abnormalities, infectious diseases such as severe acute respiratory syndrome-coronavirus 2 infection, and vascular inflammation. This pathological condition may be a reason for hyperacute thrombosis.