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.

Blood Flow Pattern Analysis for Carotid Plaque Evaluation.

BACKGROUND AND PURPOSE: Previous studies suggested that turbulent flow is closely related to plaque vulnerability. Two-dimensional (2D) flow analysis is a novel modality that enables real-time blood flow analysis by picturing particle movement in the contrast medium. We evaluated flow patterns in the carotid plaque to investigate the correlation between blood flow and plaque vulnerability. MATERIAL AND METHODS: A total of 36 consecutive patients with cervical carotid artery stenosis were evaluated. The flow pattern of carotid artery stenosis was evaluated using 2D real-time flow analysis in the digital subtraction angiography (DSA). The flow pattern was classified into either turbulent or laminar flow as vectors. Plaque vulnerability was evaluated on MR plaque imaging. Univariate analysis was performed to assess the correlation between the flow pattern and plaque features. RESULTS: The turbulent pattern was identified in 28 of 36 plaques (77.8%). Turbulence around plaques was significantly associated with Gadolinium enhancement (P = .0004). The maximum degree of stenosis (P = .0005) and concomitant ulceration (P = .02) were significantly associated with the turbulent pattern. There was no relationship between the turbulent pattern and clinical neurological symptoms. CONCLUSIONS: In the present study, the majority of carotid plaques exhibited a turbulent flow pattern, which was significantly associated with Gadolinium enhancement on MR plaque imaging and morphologic factors. Thus, real-time flow analysis may clarify the pathophysiology of plaque instability and the formation of ulceration.