Shinichi Yoshimura

Background Hemorrhagic transformation after recanalization is a severe complication in patients with a large ischemic core due to cerebral large vessel occlusion. Risk assessment using perfusion imaging to predict hemorrhagic infarction has not been established. Thus, we aimed to investigate the association between perfusion imaging findings and hemorrhagic transformation in patients with acute cerebral large vessel occlusion who had undergone preoperative perfusion imaging evaluation and mechanical thrombectomy. Methods We enrolled consecutive patients who received mechanical thrombectomy after undergoing perfusion imaging for anterior large vessel occlusion from May 2019 to March 2022. The patients in whom recanalization were not achieved and who experienced procedure‐related bleeding were excluded. We investigated the predictors of symptomatic intracranial hemorrhage (sICH) by exploring preoperative perfusion imaging parameters (relative cerebral blood flow, relative cerebral blood volume, time of maximum concentration, and hypoperfusion index ratio). Results Among the 167 patients (median age 79 years, 47% female) enrolled, 63 (38%) and 14 (8%) patients had any intracranial hemorrhage and sICH (sICH group), respectively. The sICH group had a shorter puncture‐recanalization time than the non‐sICH group (median [interquartile range (IQR)]; 43 [34–55] versus 61 [37–88]; P =0.046), whereas the modified Rankin scale at 90 days showed a worse prognosis (median [IQR]; 5 [5–6] versus 3 [1–4]; P <0.01). All perfusion imaging parameters were significantly predicting the sICH group in multiple logistic regression analysis. The value of relative cerebral blood volume was the parameter most strongly associated with sICH in receiver operating characteristic curve analysis (area under the curve=0.90, 95% CI [0.83–0.98]; cutoff 43 mL; sensitivity, 86 %; specificity, 87%). Conclusion Among perfusion computed tomography parameters, relative cerebral blood volume is highly associated with sICH after mechanical thrombectomy for cerebral large vessel occlusion. In patients with low relative cerebral blood volume regions, the indication of mechanical thrombectomy should be carefully considered for postoperative intracranial hemorrhage.