Contrast extravasation on Dyna-CT as a predictor of malignant brain edema after mechanical thrombectomy for acute anterior circulation large vessel occlusion

Background Contrast agent extravasation detected on immediate post-thrombectomy flat-panel detector computed tomography (Dyna-CT) may reflect blood–brain barrier disruption and microcirculatory dysfunction following mechanical thrombectomy (MT) for acute anterior circulation large vessel occlusion (AC-LVO). This study aimed to determine whether contrast extravasation on Dyna-CT after successful MT is associated with the subsequent development of malignant brain edema (MBE). Methods A retrospective study was conducted in AC-LVO patients who underwent MT with successful recanalization between January 2020 and December 2023. Dyna-CT was performed immediately after MT, followed by serial head CT scans. MBE was defined as acute cerebral swelling with a midline shift ≥5 mm accompanied by radiological signs of brain herniation. Patients were divided into MBE and non-MBE groups. Multivariable logistic regression analyses were performed to identify independent predictors of MBE and construct a predictive model. Results A total of 174 patients (median age, 71 years) were included, with an MBE incidence of 23.6% (41/174). Core infarct volume, baseline NIHSS score, collateral circulation, number of thrombectomy passes, and contrast extravasation were independent predictors of MBE (all P < 0.05). The combined predictive model showed excellent discrimination (AUC = 0.90, 95% CI: 0.85–0.96). Conclusion Immediate Dyna-CT detection of contrast extravasation serves as a valuable imaging biomarker for predicting MBE in AC-LVO patients after successful MT, offering timely guidance for early risk identification and individualized management.