 Designed by University of California, Los Angeles in 2001, MERCI was the first device approved in the U.S. to remove blood clots in patients suffering from acute brain ischemia.It may result in benefit in certain people as long as 8 hours after the ischemic event.In this carefully selected group it achieved 48% vessel re-canalization and lower mortality rates than the use of r-tPA in revascularized patients.