Early venous filling after reperfusion therapy in acute ischemic stroke

Background and purpose Early venous filling after endovascular mechanical thrombectomy in acute ischemic stroke (AIS) is a specific finding that may serve as a biomarker for intracranial hemorrhage. However, the pathophysiology of early venous filling and postoperative hemorrhage remains unclear. The aim of this study was to investigate correlation between early venous filling and various factors involving patient demographics and perioperative imaging. Methods We prospectively analyzed 35 patients with AIS due to cardioembolism (CE) who underwent successful acute revascularization (TICI ≥2). Ischemic lesions were scored by magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI). Outcomes were assessed using the modified Rankin Scale (mRS) 90 days after stroke onset. Blood flow analysis was evaluated by MRI with arterial spin labeling (ASL). Early venous filling was assessed by digital subtraction angiography (DSA). Univariate analysis was performed to investigate correlations between early venous filling and patient demographics and imaging findings. Results Early venous filling was observed in 22 of 35 (66%) patients after reperfusion therapy. There was a significant correlation between early venous filling and DWI-ASPECTS (6.2 vs 8.8, p=0.0003), outcome (5 vs 9, p=0.006), hyperperfusion (17 vs 1, p< 0.0001), and hemorrhagic transformation (17 vs 1, p=0.005). Conclusions This comprehensive study revealed that early venous filling after reperfusion therapy is associated with postoperative hyperperfusion. Early venous filling may be a marker of the process of hyperperfusion, leading to hemorrhage and an unfavorable outcome. Detection of early venous filling may be an important finding on DSA for subsequent intensive perioperative management.