Stroke Center Innovators Buy Time, Save Brain

Twenty years ago, most emergency room doctors considered stroke victims as candidates for rehabilitation, not treatment. And that’s if they survived.

Ischemic stroke, or blocked blood flow that starves brain cells of oxygen, was untreatable. Hemorrhagic stroke, or bleeding that causes damaging or deadly pressure on the brain, was treatable only with invasive surgery.

“Stroke was not even treated as an emergency. We just took these patients and assigned them to the back of the E.R.,” recalls Jeffrey Saver, M.D., co-director of the UCLA Stroke Center and director of stroke neurology and the stroke unit at UCLA Medical Center. “It was incredibly frustrating and sad. You really couldn’t do anything for them.”

Today, stroke is the third leading cause of death in the United States and the leading cause of disability among adults. Two-thirds of stroke victims are older than 65, and as the population ages, the number of strokes per year is expected to double by 2050.

The need is acute, but the UCLA Stroke Center team has emerged as a leader in the effort to address that need. Home to one of only seven acute stroke research centers funded by the National Institutes of Health, UCLA offers the latest approaches to prevention, diagnosis and treatment of both ischemic and hemorrhagic stroke, complemented by a long history of innovation and invention in the field.

“UCLA Medical Center houses one of the world’s most powerful multidisciplinary stroke programs – a program without walls that draws on the expertise of neurologists, surgeons, radiologists, nurses and basic scientists,” says Saver, a professor of neurology at the David Geffen School of Medicine at UCLA. “In terms of the simultaneous breadth and depth of the program, we are unique in the country.”

Clearing the Clog

In 1996, the Food and Drug Administration (FDA) approved the first clot-busting medication designed for treating ischemic stroke – recombinant tissue plasminogen activator, or rt-PA. This major breakthrough has been tempered, however, by a narrow three-hour treatment window. By the time most patients recognize the problem, arrive at a hospital and receive a diagnosis, the window of opportunity has slammed shut.

Seeking a faster solution with a more forgiving treatment window, a UCLA research team led by Y. Pierre Gobin, now a professor at Weill Cornell Medical College, set about creating a mechanical device that could quickly and safely pull clots from blocked arteries in the brain. Ultimately, the team introduced the Mechanical Embolus Removal in Cerebral Ischemia (MERCI) Retriever.

“The MERCI clot-retrieval device is not only the first device to obtain approval for use in acute stroke, it can be used beyond the three-hour limitation of rt-PA,” says Gary Duckwiler, M.D., a professor of interventional neuroradiology at the David Geffen School of Medicine and part of the original UCLA development team. “This additional option for acute stroke therapy has saved lives and reversed many disabling strokes.”

Made of a flexible titanium alloy, the MERCI Retrieval System is inserted via a catheter through the femoral artery in the upper thigh and guided to the clot location via angiography, or X-ray. When deployed, the helical corkscrew at the end of the system gently dislodges and removes the clot the way a plumber’s snake might pull a clog from a drain.

The FDA approved the device in 2004 for use within eight hours after the onset of stroke. Licensed and marketed by Mountain View, California-based Concentric Medical Inc., the device is now used by at least 200 centers throughout the United States.

“Time lost is brain loss in acute stroke,” Duckwiler says. “And now we have an option that allows us to treat a wide segment of patients acutely and maximize recovery.”

Preventive Maintenance

Hemorrhagic strokes occur when abnormalities in blood vessels rupture, and the resulting blood flow causes damaging or deadly pressure on the brain. Intracranial aneurysm, a ballooning of a brain artery caused by a weakened vascular wall, is a common cause.

For many years, preventive repair required an invasive craniotomy and manual clipping, or sealing, of the aneurysm to ease pressure on the weak spot in the artery. Such surgery is often risky or impossible due to other health issues or the aneurysm’s location.

In the early 1990s, UCLA stroke center doctors became the first to develop a minimally invasive treatment solution: the Guglielmi Detachable Coil (GDC).

“UCLA Medical Center houses one of the world’s most powerful multidisciplinary stroke programs – a program without walls that draws on the expertise of neurologists, surgeons, radiologists, nurses and basic scientists.”

“The impact of the GDC was absolutely revolutionary,” says Fernando Vinuela, M.D., co-director of the UCLA Stroke Center and UCLA professor of radiological sciences.

“This technology was safe, predictable and within three years became the gold standard.” The team included Vinuela, Guido Guglielmi, M.D., now with the University of Rome (Italy) Medical School, and Ivan Lepetska, a mechanical engineer from Target Therapeutics Inc.

Approved by the FDA in 1995, the soft, platinum micro-coil is delivered through a narrow vascular catheter and detached inside the aneurysm using a low-voltage electrical current to dissolve the connection between the wire and the coil. Once in place, the GDC coil creates a dam that isolates the weakened vascular wall from blood flow, reducing the likelihood of a rupture and hemorrhagic stroke.

Licensed initially by Target Therapeutics, which was purchased by Fremont, Calif.-based Boston Scientific Corp., the GDC has been installed in more than 400,000 patients since 1991, and today the device is used to treat up to 55 percent of all hemorrhagic stroke victims in the United States and 95 percent in Europe.

But leave it to UCLA to improve on the gold standard of care.

In 2004, the FDA approved the Matrix Detachable Coil, a product developed by a UCLA-Boston Scientific team led by Vinuela and Yuichi Murayama, UCLA adjunct associate professor of radiological sciences. The three-dimensional Matrix coil seats more securely within the aneurysm sac when deployed, and is coated with a bio-absorbable polymer that encourages the growth of protective connective tissues within and across the neck of the aneurysm.

The Right Information, the Right Decision

Whether the treatment window is three hours or eight, up-to-date information about the patient’s condition is critical. Time lost gathering lab results, X-rays, or nurse’s notes or reviewing the information can cause critical delays in care.

“The ability to speed a neurologist’s review of a stroke patient’s CT scan remotely can save 45 minutes of a three hour window. That’s enough time to get the patient the rt-PA if it is indicated,” says Neil Martin, M.D., UCLA professor and chief of the Division of Neurosurgery.

A team of three UCLA professionals with extensive backgrounds in clinical medicine, intensive care, software development, and medical-information technology came up with a better way to deliver the right patient data where and when the doctor needs it. Led by Martin and working with Val Nenov, Ph.D., and Farzad Buxey, the team developed a system that enables doctors to instantly get the right information for each patient’s condition on their cell phone or other handheld device.

“If we can guide doctors to the patients who need attention at 10 p.m. to prevent a 2 a.m. emergency call, both the doctor and the patient win,” Martin says.

Global Care Quest Inc. licensed the technology and creates software that lets clinicians get at the patient data in the way they need it, when they need it, wherever they are.

“It’s tremendously exciting and rewarding to practice with a team capable of making a significant difference in the lives of so many of our patients here at UCLA and around the world,” Saver says.