Case of malignant brain edema despite successful recanalization after mechanical thrombectomy for anterior circulation stroke

Background: Therapeutic reperfusion with endovascular treatment (EVT) for acute ischemic stroke is typically associated with better long-term functional outcome compared to standard medical care. However, post-procedural brain edema remained present in around half of EVT patients. Malignant brain edema (MBE) is a serious condition that can lead to increased intracranial pressure, rapid neurologic deterioration, and cerebral herniation, neutralizing the favorable efficacy of EVT on functional outcomes. Case Description: A 51-year-old man with a history of atrial fibrillation presented with acute onset of hemiplegia and severe bradyarrhythmia. A head computed tomography-scan demonstrated hyperdense middle cerebral artery (MCA) sign. Intravenous thrombolysis was administered before temporary pacemaker insertion. The digital subtraction angiography confirmed occlusion of the M1 branch of the right MCA with no collaterals in the territory of the occluded vessel. Mechanical thrombectomy (MT) was performed 6 h after onset and successfully achieved modified thrombolysis in cerebral infarction 3 revascularization in 6 h 20 min. The patient later experienced massive brain edema that required emergent decompressive craniectomy. The modified Rankin scale score was 4 in 1- and 3-month’s follow-up. Conclusion: MBE after MT results in unsatisfactory functional outcomes, even if it has successful revascularization. No collateral in the territory of the occluded vessel in the initial angiogram is one of the predictors of MBE after MT.