Prediction of Malignant Brain Edema Based on Contrast Agent Exudation After Mechanical Thrombectomy for Anterior Circulation Occlusion

Objective: Malignant brain edema (MBE) after mechanical thrombectomy (MT) for anterior circulation occlusion leads to poor outcomes. Although contrast agent extravasation (CAE) indicates blood-brain barrier disruption, its predictive value for MBE remains uncertain. This study evaluated whether the CAE—Alberta Stroke Program Early CT Score (CAE-ASPECTS) derived from dual-source computed tomography (CT) could predict MBE after anterior circulation recanalization with MT. Methods: Patients with anterior circulation occlusion undergoing mechanical thrombectomy (MT) were divided into malignant brain edema (MBE) and non-MBE groups. The primary outcome was to determine whether postoperative CAE-ASPECTS scores predicted MBE. The secondary outcomes were to identify factors influencing malignant brain edema and to examine the association between CAE-ASPECTS and 90-day modified Rankin Scale (mRS) and 72-hour intracerebral hemorrhage. Results: The MBE group had a significantly lower median postoperative CAE-ASPECT score. After adjusting for confounding factors, CAE-ASPECTS remained independently associated with MBE. Lower CAE-ASPECTS, higher National Institutes of Health Stroke Scale (NIHSS) score, and longer operative time were associated with increased MBE risk. The regression model yielded a predictive accuracy of 93%. Favorable 90-day mRS (0 to 2) was more common in the non-MBE group, and mortality was lower. Finally, cerebral hemorrhagic transformation was inversely correlated with CAE-ASPECTS. Conclusion: Lower CAE-ASPECTS scores were significantly correlated with increased MBE incidence. Moreover, CAE-ASPECTS was an independent predictor of MBE, while cerebral hemorrhage transformation was negatively correlated with the CAE-ASPECTS after successful thrombectomy. Finally, CAE-ASPECTS, preoperative NIHSS, ASPECTS, and operative time collectively predict MBE with 93% sensitivity, providing a useful imaging biomarker for post-MT risk assessment.