Pseudo-Occlusion of the Internal Carotid Artery Predicts Poor Outcome After Reperfusion Therapy

Background and Purpose— This study aimed to evaluate the occurrence rate of the internal carotid artery pseudo-occlusion (ICA-PO) on 4-dimensional–computed tomography angiography and to investigate its relationship with clinical outcome after reperfusion therapy. Methods— In this case–control study, we retrospectively reviewed our prospectively collected database for consecutive acute ischemic stroke patients who received reperfusion therapy between June 2009 and February 2017. ICA-PO was defined when the arterial segment was not opacified on peak arterial phase yet was subsequently patent after artery peak phase on 4-dimensional–computed tomography angiography. Poor outcome was defined as 3-month modified Rankin Scale of 4 to 6. Binary logistic regression was used to investigate the relationship of ICA-PO with poor outcome and the rate of reperfusion, respectively. Results— A total of 143 patients with isolated middle cerebral artery occlusion were included and 30 (21.0%) had ICA-PO. Patients with ICA-PO were more likely to have poor outcome (80.0% versus 37.2%;P <0.001) and a lower rate of reperfusion (45.8% versus 69.0%;P =0.033) than those without. Binary logistic regression revealed that ICA-PO was independently associated with poor outcome (odds ratio, 7.957; 95% confidence interval, 1.655–34.869;P =0.009) and reperfusion at 24 hours (odds ratio, 0.150; 95% confidence interval, 0.045–0.500;P =0.002) after adjustment. Among patients with no reperfusion, all ICA-PO patients obtained poor outcome, whereas only 45.2% non-PO patients underwent poor outcome (P =0.001).Conclusions— Four dimensional-computed tomography angiography is a useful noninvasive technique to identify ICA-PO. Patients with ICA-PO are prone to undergo poor outcome from reperfusion therapy, especially when reperfusion is not achieved.