Since stent grafting has been an effective way to treat other aortic conditions such as aneurysms (bulge in aorta wall), it is believed that the Valiant stent graft would be effective in treating BTAI. A stent graft is a woven polyester tube (graft) supported by a metal frame of strong but flexible nitinol (type of metal) springs (stent) that is placed in the aorta to help seal the injury and keep it from bleeding.