Angiographic Pattern of M1 Stenosis Predicts Territorial Stroke in Patients Receiving Aggressive Medication without Stenting

To evaluate the relationship between different angiographic patterns of middle cerebral artery M1 segment stenosis and related territorial stroke in patients receiving aggressive medical treatment without stenting. We retrospectively reviewed our patient registry database to identify ICAS patients diagnosed by digital subtraction angiography between January 2017 and December 2020 and identified 3 different angiographic patterns (normal, shift, and dilation) in 124 patients with M1 stenosis. The association between these patterns and recurrent ischemic stroke in the M1 territory was analyzed. The rates of recurrent M1 territorial stroke and transient ischemic attack in the normal group, shift group, dilation group and shift-dilation group were 34.5%, 35.0%, 78.3%, and 44.4% respectively. In patients with the shift pattern, the rate of recurrent stroke is significantly higher at a deflection angle ≥9.32° than at a deflection angle <9.32°(P < 0.05). In patients with dilation pattern, the rate of recurrent stroke is significantly higher than patients with non-dilation pattern (72.3% vs. 36.8%, P < 0.05). Angiographic patterns of M1 stenosis may predict recurrent territorial strokes, thus providing a surrogate marker to identify high-risk patients for potential endovascular treatment.