Effect of Perforator Territory Infarction on Functional Outcome in Patients With Large Vessel Occlusion

BACKGROUND: Knowledge of the anatomic distribution of cerebral perforating arteries and the consequences of ischemia in these territories is limited. This study aims to evaluate the effect of perforator territory ischemia on functional outcome in patients with anterior circulation large vessel occlusion. METHODS: A post hoc analysis of the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands, MR CLEAN-MED and NO IV participants, recruited between January 2018 and January 2021 from 20 European stroke centers, was performed. Patients undergoing endovascular thrombectomy for anterior circulation large vessel occlusion with available posttreatment magnetic resonance imaging were included. Patients were assigned to 3 groups based on infarct location identified on ≤24 hours posttreatment magnetic resonance imaging: cortex group, perforator and insular group, and both groups (cortical alongside insular and perforator territory). Multivariable linear and ordinal regression analyses were performed separately with the National Institutes of Health Stroke Scale score at 24 hours as the primary outcome and modified Rankin Scale at 90 days as the secondary outcome, adjusted for baseline scores and prognostic factors. RESULTS: Out of 1167 patients, a total of 397 were included. The median age was 71 (interquartile range, 62–79), and 204 (51%) were men. Although no significant association was found in multivariable analysis between perforator territory infarctions and 24 hours National Institutes of Health Stroke Scale, patients with perforator territory ischemia were more likely to have a worse 90-days modified Rankin Scale (median modified Rankin Scale, 2 [interquartile range, 1–3]; common odds ratio, 2.94 [95% CI, 1.73–4.98]). Besides infarct locations, Thrombolysis in Cerebral Infarction grade 2B-3 and Heidelberg bleeding classifications 1c and 2 significantly influenced the 24-hour National Institutes of Health Stroke Scale and 90-day modified Rankin Scale outcomes. CONCLUSIONS: Patients with anterior circulation large vessel occlusion leading to perforator territory infarctions are more likely to have an unfavorable functional outcome at 90 days. Future research should focus on better visualization of perforating arteries and understanding their functional anatomy to prevent perforator territory ischemia and improve patient outcomes.