Anthony J. Furlan, MD, Chairman of Neurology and Co-Director of the Neurological Institute at University Hospitals (UH) Case Medical Center and Case Western Reserve University School of Medicine, who writes an accompanying editorial for five studies about endovascular stroke therapy published simultaneously in the New England Journal of Medicine, says these randomized clinical trials represent a breakthrough in showing the benefits of endovascular therapy for acute ischemic strokes.

"Now even endovascular skeptics will be convinced," Dr. Furlan writes.

His editorial, entitled Endovascular Stroke Therapy: It's About Time, states that these trials demonstrate the therapy is highly beneficial in a "resounding fashion."

The studies compared endovascular therapy - administration of an intravenous clot-busting agent (tPA) followed by device removal of a clot blocking a brain artery - with the clot-busting agent IV tPA alone for the treatment of ischemic stroke.

Dr. Furlan says that these new studies should settle any lingering uncertainties that have existed over endovascular therapy (also known as intra-arterial therapy), especially since three studies in 2013 indicated the therapy was no more effective than IV tPA alone.

He attributes the difference in results in the new studies to three things: Superior surgical technology resulting in faster, more complete clearage of the blockage; heightened awareness of decreasing the amount of time between patient arrival in the emergency department to the start of the endovascular procedure, and improved neuroimaging criteria for selecting patients most likely to benefit from the therapy.

Dr. Furlan says these studies represent a paradigm shift reminiscent of the introduction of the clot-busting therapy IV tPA in the 1990s.

"However, a major difference between then and now is that a stroke infrastructure is already in place in many countries due to the introduction of tPA during the past 20 years. Now, our stroke systems must adapt to endovascular therapy."

As with tPA, only a small percentage of stroke victims will need endovascular therapy (about 10 percent), according to Dr. Furlan, and not every hospital can or should perform it. Every year, more than 795,000 people in the United States have a stroke, according to the Centers for Disease Control and Prevention.

"This therapy will have major implications for Emergency Medical Services (EMS) triaging decisions because endovascular candidates should now be directly transported to a Comprehensive Stroke Center whenever possible, as rapidly as possible."

"As a result of these studies, the real winners are our patients with devastating strokes," Dr. Furlan says.

Dr. Furlan is a leading authority on stroke and was the Principal Investigator for PROACT II (Prolyse in Acute Cerebral Thromboembolism Trial II) which established the proof of principle of intra-arterial thrombolysis beyond 3 hours. He was the North American Principal Investigator for the DIAS/DEDAS trials (Desmoteplase in Acute Ischemic Stroke). He chaired the NIH/NINDS Hospital Care of Acute Stroke Task Force in 1996 at the National Symposium on the Rapid Identification and Treatment of Acute Stroke and was instrumental in establishing treatment time targets for IV tPA.