A device and method for protecting a blood vessel. The device (7) may be astent (2), for insertion in a large artery such as the ascending aorta (1),and may be combined with a filter (16). The device includes an outer wireframe rather than a stent.The stent may be made of at least one layer of mesh(12), which is typically attached or mounted to the arterial wall. Typicallythe size of the apertures of the mesh (12) at the top portion of the stent issmaller than the bottom portion of the stent. The device and method areparticularly useful in preventing blockages of flow to the brain, but haveother uses as well. An electric charge (14) may be placed on the device, forexample, to prevent blood components from collecting.