Semi-quantitative and qualitative evaluation of pial leptomeningeal collateral circulation in acute ischemic stroke of the anterior circulation: the Careggi Collateral Score.

The imaging of ischemic penumbra in acute stroke is a debated issue and establishing commonly accepted criteria is difficult. Computerized tomography-perfusion studies conducted in animals have showed that the modifications occurring in the brain parenchima are part of a dynamic and progressive process involving the microcirculation. The purpose of this paper is to propose a new angiographic classification of collateral circulation in patients with acute ischemic stroke, with a possible correlation with the clinical outcome.The basal angiograms of 57 patients with acute ischemic stroke is the territory of anterior circulation secondary to a major occlusion, who underwent endovascular treatment, were retrospectively reviewed and collaterals were classified according to our novel Careggi Collateral Score in 6 grades (0-6). The clinical outcome after 3 months was evaluated with modified Rankin Scale. A ROC (receiver operating characteristic) curve analysis identified a cut-off value of 1.Patients with favorable collateral circulation (grades 2-5) showed a significant correlation with good clinical outcome (modified Rankin Scale < or = 2).The Careggi Collateral Score resulted a useful tool to evaluate the chance of obtaining a favorable result with endovascular treatment in patients with acute ischemic stroke in the anterior circulation secondary to the occlusion of a major artery.