Endovascular treatment in patients with middle cerebral artery occlusion of different aetiologies

Purpose The purpose of this study was to evaluate differences in endovascular treatment (EVT) outcomes in M1 segment middle cerebral artery occlusion (MCAO) patients with different pathologic subtypes. Methods Patients with MCAO who received EVT from July 2014 to December 2020 were categorized into three groups: embolism without internal carotid artery steno-occlusion (MCAO-E), in situ atherosclerotic thrombosis (MCAO-AS) and embolism from tandem ICA steno-occlusion (MCAO-T). Baseline characteristics, EVT-related factors and clinical outcomes were compared between groups. Multivariable regression analyses were performed to evaluate the relationship between aetiologic classification and outcomes at 90 days after stroke. Results Among eligible patients (n = 220), MCAO-E (n = 129, 58.6%) was the most common aetiology, followed by MCAO-AS (n = 47, 21.4%) and MCAO-T (n = 44, 20.0%). Patients with MCAO-E were significantly older but had a lower rate of dyslipidaemia and smoking history than those with MCAO-AS. Although patients with MCAO-AS and MCAO-T more often required rescue balloon angioplasty and stenting (p < 0.001), no significant difference in the rate of final recanalization was found. Patients in the MCAO-AS group obtained better functional outcomes (90-day modified Rankin Scale score, 0-2) (p = 0.002) and lower mortality than in the MCAO-E group (p = 0.009). On multivariable logistic regression, we failed to find that stroke subtype was an independent predictor of functional outcomes and mortality. Conclusions Patients with acute MCA M1 occlusion stroke due to different pathogeneses had comparable successful recanalization rates and functional independence at 90 days. The optimal management for MCAO patients with different aetiologies requires further research.