Pooled blood volume measured by final flat-panel detector computed tomography predicts outcome after endovascular thrombectomy for acute ischemic stroke

Background: Pooled blood volume (PBV), measured in real-time in the angiography room using an angiography system, correlates with cerebral blood volume (CBV). We examined the usefulness of PBV in endovascular thrombectomy (EVT) for acute ischemic stroke (AIS). Methods: EVT for AIS in the anterior circulation (internal carotid artery (ICA) and middle cerebral artery (MCA)) was performed in 31 cases (13 males, 18 females, average age 75.7 years). PBV was acquired using a biplane flat-panel detector (FD) angiographic system. Then, we measured the average PBV value in the M1-6 regions similar to the Alberta Stroke Program Early CT score (ASPECTS) before and after EVT. We investigated factors associated with favorable outcome at 90 days after EVT. Results: There were 13 patients (41.9%) in the good outcome group (mRS (modified Rankin Scale) ≦2) and 18 patients (58.1%) in the poor outcome group (mRS>2). In univariate analysis, NIHSS (National Institutes of Health Stroke Scale) (odds ratio [OR] 0.74, 95% CI 0.57–0.87, p < 0.0001) and post PBV value (odds ratio [OR] 1.13, 95% CI 1.03–1.29, p = 0.0086) were significantly associated with good outcome. The good outcome group had significantly higher post-thrombectomy PBV value (3.69 ± 0.32 ml/100 g versus 2.78 ± 0.93 ml/100 g, P = 0.002) compared to that of the poor outcome group. The relationship between pre-thrombectomy PBV value and outcome at 90 days was not significant. Conclusions: Post-operative PBV value measured by FD-CT (computed tomography) correlated with 90-day outcome after EVT for AIS. FD-CT-PBV would be one of the good predictors of clinical outcome.