Comprehensive Venous Outflow Evaluation Predicts Stroke Outcome After Optimal Endovascular Ischemic Stroke Treatment

Large vessel occlusion (LVO) acute ischemic stroke represents a leading cause of disability despite successful endovascular treatment (EVT). Venous outflow has recently emerged as a potential predictor of functional outcome in ischemic stroke. We aimed to investigate whether a comprehensive venous drainage evaluation is associated with stroke evolution and functional outcome. Prospective study on acute stroke patients with anterior LVO who underwent optimal recanalization from February 2023 to February 2024. Opacification and drainage time of superficial and deep veins were evaluated on digital subtraction angiography sequences. Clinical outcome was functional recovery at 90 days, whereas neuroradiological outcomes were ischemic lesion growth (ILG) and hemorrhagic transformation (HT). Multivariate logistic and linear regression models were performed. 24/50 patients (48%) displayed an unfavorable outcome, 14/50 (28%) a HT, and 28/50 (56%) an ILG. Longer median washout times of the superficial venous system were independently associated with a higher risk of poor functional outcome (aOR = 1.32; 95% CI 1.02-1.79; p = 0.049), ILG (aB = 3.06; SE 1.26; p = 0.020) and HT (aOR = 1.65; 95% CI 1.21-2.47; p = 0.005), and cortical frontal veins were the best predictor within veins' group. Opacification of Labbè and superficial middle cerebral veins predicted only HT (aOR = 0.178; 95% CI 0.026-0.766, p = 0.041) and ILG (aB = 9.78; SE 2.75; p = 0.003), respectively. In this cohort of LVO acute ischemic stroke patients with an optimal recanalization after EVT, qualitative and quantitative aspects of venous outflow were independent predictors of stroke evolution and functional outcome. A comprehensive venous outflow evaluation represents a potential target for a tailored management of patients after EVT.