Supplementary Material for: Radiographic signs of advanced cerebral venous thrombosis negatively modulate the effectiveness of endovascular treatments

Introduction: Endovascular treatment (EVT) is a therapeutic option for cerebral venous thrombosis (CVT); however, its benefit over conservative medical management has not been proven. Whether current patient selection practices are appropriate for EVT is unclear. Methods: This was a nationwide study of the 2016-2020 National Inpatient Sample database. Adult CVT patients and EVT treatments were identified. Patient demographics, medical comorbidities, CVT risk factors, and CVT manifestations were identified. Presence of radiographic signs of advanced and severe CVT (venous infarction, cerebral edema, and intracranial hemorrhage) were recorded. Primary and secondary outcomes were good discharge outcomes and in-hospital mortality, respectively. Results: 17,130 CVT patients were identified, and 56.7% had good discharge outcomes while 4.6% died during hospitalization. 945 (5.5%) received EVT, and EVT patients were more likely to have cerebral infarction (35.4% vs. 21.8%, p<0.001), edema (35.4% vs. 20.1%, p<0.001), and hemorrhage (37.6% vs. 19.7%, p<0.001). After multivariable adjustments, EVT for patients without infarction, edema, or hemorrhage was moderately associated with higher odds of good outcomes (OR 1.86 [95%CI 0.98 - 3.53], p=0.059) and resulted in zero deaths. However, with increasing burden of radiographic signs of advanced CVT measured by the cumulative presence of infraction, edema, and hemorrhage, EVT was associated with decreasing odds of good outcomes and increasing odds of in-hospital mortality compared to medical management (interaction p=0.046 and 0.029, respectively). Conclusions: EVT may lead to higher rates of favorable hospitalization outcomes in patients who have not yet developed overt parenchymal manifestations of backpressure changes; presence of infarction, edema, and hemorrhage may diminish the short-term effectiveness of EVT.