In the October issue of the "Lancet Neurology", Suhaib A et al discussed the potential benefit of augmenting or maintaining the cerebral collateral circulation in case of ischaemic stroke. The article which was published on line today mentioned that "Imaging of the brain and vessels has shown that collateral flow can sustain brain tissue for hours after the occlusion of major arteries to the brain, and the augmentation or maintenance of collateral flow is therefore a potential therapeutic target. Several interventions that might augment collateral blood flow are being investigated".

http://www.thelancet.com/journals/laneur/article/PIIS1474-4422(11)70195-8/abstract