P008 Bihemispheric involvement is associated with unfavorable functional outcome after endovascular treatment of cerebral vasospasm following aneurysmal subarachnoid hemorrhage

<h3>Introduction</h3> Cerebral vasospasms (CV) remain a significant predictor of poor outcome after aneurysmal subarachnoid hemorrhage (aSAH). <h3>Aim of Study</h3> This study aims to analyze patients’ individual risk factors, intensity and extend of CV associated with poor functional outcome after aSAH. <h3>Methods</h3> We conducted a retrospective study of consecutive patients with aSAH admitted at a tertiary stroke center between January 2016 and December 2022. Patients with medically refractory CV necessitating at least one endovascular intervention were analyzed. Primary endpoint was defined as functional outcome defined as modified Rankin Scale (mRS) scores after 6 months. Secondary endpoint was the occurrence of cerebral infarctions following CV. <h3>Results</h3> Overall, 138 patients received EVT due to CV, including 322 treatments with 78 patients receiving more than one EVT. In 65.2% (90) patients developed CV in both hemispheres, in 16.7% (23) CV occurred involved the posterior circulation, and in 10.1% (14) PTA was performed. Multivariable logistic regression analysis showed an association of older age (adjusted odds ratio [aOR], 1.05, 95% CI, 1.0-1.1), higher Hunt&amp;Hess grades (aOR, 2.12, 95% CI, 1.38-3.24), the occurrence of rebleeding (aOR, 4.97, 95% CI, 1.0-24.65), and bihemispheric vasospasm (aOR, 4.05, 95% CI, 1.4-11.72), with unfavorable outcome (mRS 3-6). Further analysis showed that older higher age (aOR, 1.07, 95% CI, 1.03-1.13) was associated with an increased risk for developing vasospasm-associated infarctions. <h3>Conclusion</h3> Our results indicate an association between bihemispheric CV and poor functional outcome after aSAH. This finding supports a more aggressive treatment strategy in patients developing bihemispheric vasospasm to prevent unfavorable disease courses. <h3>Disclosure of Interest</h3> no.