Abstract Number ‐ 22: Hemorrhagic Outcomes in Patients Demonstrating Early Venous Filling After Mechanical Thrombectomy For Acute Ischemic Stroke

Introduction Endovascular thrombectomy (EVT) for acute ischemic infarcts with large vessel occlusion have been shown to improve functional outcomes. However, there is still the risk of hemorrhagic transformation (HT). Early identification of patients at risk of HT is paramount to enhance EVT outcomes. EVF can be an indicator of the hyperemia that occurs following an infarct. We evaluated if early venous filling (EVF) defined as contrast filling of any cerebral vein within the arterial phase on angiogram can predict individuals at a higher risk of HT after EVT. Methods From the SELECT cohort,EVT patients with evaluable digital subtraction angiography were included in the study. Baseline clinical and imaging characteristics as well as clinical and hemorrhagic outcomes were compared between patients demonstrating EVF and no EVF. Association between EVF with symptomatic ICH and parenchymal hemorrhage was examined using multivariable logistic regression models. Results 46/254 (18%) patients had EVF at the end of the procedure. Age and NIHSS were similar between the patients with and without EVF, although patients with EVF presented earlier (1.39 (0.88‐2.75) hours vs 2.62 (1.10‐4.28) hours, p = 0.024), and demonstrated lower CT ASPECTS (7 (6‐9) vs 8 (7‐9), p = 0.022). The presence of EVF was associated with significantly higher odds of sICH (EVF: 8.7% vs no EVF: 5.6%, aOR: 4.72, 95% CI: 1.05‐21.28, p = 0.043) and demonstrated a trend towards higher odds of parenchymal hemorrhage type 1 or 2 (EVF: 10.9% vs no EVF: 6.3%, aOR: 3.64, 95% CI: 0.96‐13.73, p = 0.057) and mortality (EVF: 17% vs no EVF: 12%, aOR: 3.22, 95% CI: 0.93‐11.13, p = 0.064). Functional outcomes did not differ at 90 days between the two groups Conclusions Early identification of EVF may help to identify patients with increased risk of hemorrhagic transformation after EVT. This finding was independent from time last known well. While EVF is suggestive of hyperemia it is also a biomarker of infarct volume and may help to implement early therapeutic measurements to reduce hemorrhagic transformation risk such as strict blood pressure control. Further studies to evaluate EVF as a potential marker for hemorrhagic transformation are required

SARS-CoV-2 vaccination modelling for safe surgery to save lives: data from an international prospective cohort study

Background: Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numbers are limited so this study aimed to inform their prioritization by modelling. Methods: The primary outcome was the number needed to vaccinate (NNV) to prevent one COVID-19-related death in 1 year. NNVs were based on postoperative SARS-CoV-2 rates and mortality in an international cohort study (surgical patients), and community SARS-CoV-2 incidence and case fatality data (general population). NNV estimates were stratified by age (18-49, 50-69, 70 or more years) and type of surgery. Best- and worst-case scenarios were used to describe uncertainty. Results: NNVs were more favourable in surgical patients than the general population. The most favourable NNVs were in patients aged 70 years or more needing cancer surgery (351; best case 196, worst case 816) or non-cancer surgery (733; best case 407, worst case 1664). Both exceeded the NNV in the general population (1840; best case 1196, worst case 3066). NNVs for surgical patients remained favourable at a range of SARS-CoV-2 incidence rates in sensitivity analysis modelling. Globally, prioritizing preoperative vaccination of patients needing elective surgery ahead of the general population could prevent an additional 58 687 (best case 115 007, worst case 20 177) COVID-19-related deaths in 1 year. Conclusion: As global roll out of SARS-CoV-2 vaccination proceeds, patients needing elective surgery should be prioritized ahead of the general population