Blood-brain barrier permeability by CT perfusion predicts parenchymal hematoma after recanalization with thrombectomy

Introduction: Hemorrhagic transformation (HT) is a complication of reperfusion therapy for acute ischemic stroke. Blood-brain barrier (BBB) disruption is a crucial step toward HT; however, in clinical studies, there is still uncertainty about this relation. Hence, we conducted a systematic review and meta-analysis to summarize the current evidence.Methods: We enrolled 53 patients with acute ischemic stroke who underwent mechanical thrombectomy and achieved successful recanalization. Each patient underwent CT, CT angiography, and CT perfusion imaging before treatment. We used relative volume transfer constant (rK(trans)) values, relative permeability-surface area product (rP<middle dot>S), and relative extraction fraction (rE) to evaluate preoperative blood-brain barrier permeability in the delayed perfusion area.Results: Overall, 22 patients (37.7%) developed hemorrhagic transformation after surgery, including 10 patients (16.9%) with hemorrhagic infarction and 11 patients (20.8%) with parenchymal hematoma. The rP<middle dot>S, rK(trans), and rE of the hypoperfusion area in the parenchymal hematoma group were significantly higher than those in the hemorrhagic infarction and no-hemorrhage transformation groups (p < .01). We found that rE and rP<middle dot>S were superior to rK(trans) in predicting parenchymal hematoma transformation after thrombectomy (P<middle dot>S area under the curve [AUC] .844 vs. rK(trans) AUC .753, z = 2.064, p = .039; rE AUC .907 vs. rK(trans) AUC .753, z = 2.399, p = .017).Conclusion: Patients with parenchymal hematoma after mechanical thrombectomy had higher blood-brain barrier permeability in hypoperfusion areas. Among blood-brain barrier permeability measurement parameters, rP<middle dot>S and rE showed better accuracy for parenchymal hematoma prediction.