Immediate CT change after thrombectomy predicting symptomatic hemorrhagic transformation

Background: The prognostic value of contrast accumulation from noncontrast brain computed tomography (CT) conducted immediately after intra mechanical thrombectomy (MT) in patients with acute ischemic stroke to predict symptomatic hemorrhage was studied. Methods: Patients with acute ischemic stroke treated using MT between February 2015 and April 2019 were included. Contrast accumulation was defined as a high attenuation area observed on noncontrast brain CT conducted immediately after thrombectomy treatment, and the patients were categorized into (1) symptomatic hemorrhage, (2) asymptomatic hemorrhage, and (3) no hemorrhage according to the presence of hemorrhagic transformation and their clinical conditions. The pattern and extent of contrast accumulation were compared between patients with and without symptomatic hemorrhage. The maximal Hounsfield unit (HU) of cortical involvement in contrast accumulation was evaluated by calculating the sensitivity, specificity, odds ratio, and area under the receiver operating characteristic (ROC) curve. Results: In total, 101 patients with anterior circulation acute ischemic stroke were treated by endovascular intervention. Nine patients developed symptomatic hemorrhage and 17 developed asymptomatic hemorrhage. Contrast accumulation was associated with all types of hemorrhagic transformation (p < 0.01), and cortical involvement pattern was more frequently associated with symptomatic hemorrhage (p < 0.01). The area under the ROC curve was 0.887. The sensitivity and specificity for HU > 100 in cortical involvement predicting symptomatic hemorrhage after endovascular treatment were 77.8% and 95.7%, respectively, with an odds ratio of 77.0 (95% CI, 11.94-496.50; p < 0.01). Conclusion: Cortical involvement of contrast accumulation with a maximal HU > 100 predicts symptomatic hemorrhage after endovascular reperfusion treatment.