Hyperperfusion Immediately after Reperfusion by Thrombectomy May Predict Hemorrhagic Transformation

Objective: To evaluate cerebral blood fl ow immediately after reperfusion following thrombectomy for acute large vessel occlusion, and to examine whether cerebral blood fl ow after reperfusion is related to hemorrhagic transformation. Methods: The patients with acute large vessel occlusion in the anterior circulation who obtained reperfusion by thrombectomy were included. Cerebral blood fl ow was evaluated using single photon emission computed tomography (SPECT) within 6 hours after reperfusion. The patients were divided into two groups with or without hemorrhagic transformation, and basic characteristics, the ratio of cerebral blood fl ow (aff ected-side to unaff ected-side ratio) in the perfusion area of the middle cerebral artery (MCA asymmetry index), and functional prognosis were compared among two groups. Results: In all, 23 patients were included; 11 presented hemorrhagic transformation, and 12 did not. The hemorrhagic group exhibited signifi cantly higher MCA asymmetry index than the non-hemorrhagic group (median: 1.54 [1.30–1.83] vs. 1.12 [1.07–1.24], respectively, P = 0.02), and a lower rate tendency of modifi ed Rankin Scale (mRS): 0-2 after 3 months (1 patient [9%] vs. 6 patients [50%], respectively, P = 0.06). Conclusion: In patients with successful reperfusion by thrombectomy, hemorrhagic transformation is predisposed to occur when high MCA asymmetry index is presented. Care should be taken in periprocedural management of blood pressure and sedation for those with high MCA asymmetry index.