Intraluminal Middle Cerebral Artery Occlusion (MCAO) Model for Ischemic Stroke with Laser Doppler Flowmetry Guidance in Mice

Stroke is the third leading cause of death and the leading cause of disability in the world, with an estimated cost of near $70 billion in the United States in 2009(1,2). The intraluminal middle cerebral artery occlusion (MCAO) model was developed by Koizumi(4) in 1986 to simulate this impactful human pathology in the rat. A modification of the MCAO method was later presented by Longa(3). Both techniques have been widely used to identify molecular mechanisms of brain injury resulting from ischemic stroke and potential therapeutic modalities(5). This relatively noninvasive method in rats has been extended to use in mice to take advantage of transgenic and knockout strains(6,7). To model focal cerebral ischemia, an intraluminal suture is advanced via the internal carotid artery to occlude the base of the MCA. Retracting the suture after a specified period of time mimics spontaneous reperfusion, but the suture can also be permanently retained. This video will be demonstrating the two major approaches for performing intraluminal MCAO procedure in mice in a stepwise fashion, as well as providing insights for potential drawbacks and pitfalls. The ischemic brain tissue will subsequently be stained by 2,3,5-triphenyltetrazolium chloride (TTC) to evaluate the extent of cerebral infarction(8).