Permeability-surface area product of the penumbra as a predictor of outcome after endovascular treatment of anterior circulation acute ischemic stroke

Background: Permeability-surface product is a predictor of blood–brain barrier disruption, a condition that may be related to higher likelihoods of hemorrhagic transformations in acute stroke. Purpose: To investigate whether permeability-surface product can be used as a parameter for predicting outcome after mechanical thrombectomy in patients with anterior circulation acute ischemic stroke. Material and Methods: We retrospectively identified patients with acute middle cerebral artery stroke who underwent successful mechanical thrombectomy between November 2009 and July 2015. Multiple parameters (including age) and CT perfusion-related parameters (including permeability-surface product) were compared between patients with favorable (modified Rankin Scale [mRS] = 0–2) and unfavorable (mRS > 2) outcome. Results: Thirty patients were included, 50% having favorable and 50% having unfavorable outcome. Younger age was significantly associated with favorable outcome (P < 0.03). Other baseline characteristics, such as size of CT perfusion core infarction, perfusion abnormality, and presentation of subcortical infarction were not significantly different between groups. No significant difference was observed between groups for permeability-surface product in the ipsilateral penumbra or for the ratio between permeability-surface product penumbra value and contralateral normal brain (permeability-surface product ratio). Conclusions: No significant difference was observed between patients with and without favorable outcome after mechanical thrombectomy for either permeability-surface product value or permeability-surface product ratio. Although permeability-surface product is a good predictor of blood–brain barrier disruption, this study revealed no evidence that either permeability-surface product value or permeability-surface product ratio is associated with future change in the penumbra.