Concentric Medical Announces 1,000th Patient Enrolled in the Merci Registry

MOUNTAIN VIEW, California, June 3, 2010 - Concentric Medical, Inc., the global leader in acute ischemic stroke
intervention, announced completion of enrollment in the Merci Registry with a
total of 1,000 patients enrolled. The Merci Registry is a real-world,
international, post-market study of the Merci Retrieval System(R). Since its
launch in June 2007, over 30 sites worldwide have contributed patients to the
Registry, which is the largest repository of prospectively collected
multi-center data on mechanical embolectomy in acute ischemic stroke
patients. The principal investigators for the Registry are Marilyn Rymer, MD,
Founder and Director of the Stroke Center at Saint Luke's Hospital in Kansas
City, Missouri, and Wade Smith, MD, PhD, Professor of Neurology at the
University of California at San Francisco.

Since its inception, the Registry has captured a wide variety of data,
including acute procedural data, patient care protocols, and longer term
outcomes that have played a critical role in Concentric Medical's ability to
continually improve the technical success and ease of use of the Merci
Retrieval System. Participating physicians and Concentric Medical are
analyzing patient care protocols and longer term outcomes to further the
stroke community's understanding of best practices for the acute care and
management of stroke victims. Previous interim analyses of these data were
presented at major stroke conferences including the Society for
NeuroInterventional Surgery and the International Stroke Conference and have
garnered widespread attention.

Upon enrollment of the 1,000th patient in the Registry, Dr. Rymer
commented, "The Merci Registry has already proven to be an important
benchmarking tool that has provided physicians who treat stroke with
important information on the benefits offered by mechanical intervention, as
well as insight into how best to care for patients who suffer from this
devastating disease. This data will be a rich source of knowledge that will
continue to be explored for years to come and because we are still in the
early phases of treatment of acute ischemic stroke, it will also serve as a
platform for generating new hypotheses and may ultimately help shape the
future of research and patient care."

Regarding the Merci Registry's impact on acute ischemic stroke
intervention, Maria Sainz, President and CEO of Concentric Medical, said,
"The completion of the Registry, the first of its kind in stroke intervention
with 1,000 patients enrolled in less than three years, is a significant
accomplishment. The learnings from the Registry are deep, as demonstrated by
the eight papers presented during ISC 2010. We look forward to facilitating
the analyses of the data with the stroke clinicians to advance the field of
stroke intervention."

About Concentric Medical

Concentric Medical is located in Mountain View, California and is the
global leader in the development of endovascular devices for revascularizing
stroke patients. The company manufactures and markets solutions for ischemic
stroke: minimally invasive devices that are delivered into the brain to
restore blood flow by removing blood clots that cause ischemic stroke.
Concentric Medical's devices are available in over 500 leading stroke centers
around the world, and have been the subject of several clinical studies. For
more information about Concentric Medical, please visit
www.concentric-medical.com.

About Acute Ischemic Stroke

Stroke is the third leading cause of death in the developed world and the
leading cause of serious long-term disability. Ischemic stroke represents
over 85% of strokes and occurs when a blockage or clot develops in one of the
arteries supplying blood to the brain. In 2004 the FDA cleared Concentric
Medical's Merci Retriever(R) for use in patients who are ineligible for
IV-tPA or who fail to respond to IV-tPA therapy. This pioneering device
creates a departure from the historic method of caring for stroke patients
and offers physicians and patients a long-awaited option for stroke
intervention.

    Media Contact:
    +1-650-938-2100
    strokeinfo@concentric-medical.com

Concentric Medical, Inc., +1-650-938-2100, strokeinfo at concentric-medical.com