Carotid free-floating thrombus in COVID-19: a cerebrovascular disorder of cytokine storm-related immunothrombosis

Backgrounds: Several neurological manifestations, including stroke, have been reported in COVID-19 patients. The putative role of the COVID-19-related hyperinflammatory state in cerebrovascular disorders remains unclear.

Methods: From March 2020 to September 2021, we searched for patients who exhibited an ischemic stroke related to carotid free-floating thrombus (CFFT) to investigate its incidence and relationship with COVID-19.

Results: Of 853 ischemic strokes referred to our Stroke Centre during the study period, 5.7% (n = 49) were positive for SARS-CoV-2. Six had CFFT, of which two tested positive for SARS-CoV-2 (2/49 = 4.1%), and four did not (4/802 = 0.5%). The former were two middle-aged men suffering from COVID-19 pneumonia. Floating thrombi were promptly extracted by endarterectomy and endovascular thrombectomy, respectively, with no early and long-term complications. Notably, our COVID-19 patients exhibited little or no atherosclerosis burden on CT angiography, markedly elevated D-dimer levels, and extensive thrombus length.

Conclusions: COVID-19-induced immunothrombosis possibly played a significant pathogenic role in CFFT.