ABSTRACT
Cases of cerebral venous thrombosis (CVT) associated with vaccine induced thrombotic thrombocytopenia (VITT) were reported following administration of the adenoviral vector COVID-19 vaccines, resulting in a pause in Ad.26.COV2.S vaccine administration in the United States, beginning on April 14, 2021. We aimed to quantify and characterize an anticipated increase in brain venograms performed in response to this pause. Brain venogram cases were retrospectively identified during the three-week period following the vaccine pause and during the same calendar period in 2019. For venograms performed in 2021, we compared COVID vaccinated to unvaccinated patients. There was a 262% increase in venograms performed between 2019 (n = 26) and 2021 (n = 94), compared to only a 19% increase in all radiologic studies. Fifty-seven percent of patients in 2021 had a history of COVID-19 vaccination, with the majority being Ad.26.COV2.S. All patients diagnosed with CVT were unvaccinated. COVID vaccinated patients lacked platelet or D-dimer measurements consistent with VITT. Significantly more vaccinated versus unvaccinated patients had a headache (94% vs 70%, p = 0.0014), but otherwise lacked compelling CVT presentations, such as decreased/altered consciousness (7% vs 23%, p = 0.036), neurologic deficit (28% vs 48%, p = 0.049), and current/recent pregnancy (2% vs 28%, p = 0.0003). We found a dramatic increase in brain venograms performed following publicity of rare COVID-19 vaccine associated CVT cases, with no CVTs identified in vaccinated patients. Clinicians should carefully consider if brain venogram performance is indicated in COVID-19 vaccinated patients lacking thrombocytopenia and D-dimer elevation, especially without other compelling CVT risk factors or symptoms.