"Gimmie Shelter!" Advances in Stroke Treatment

Posted by: Mike Pallante on April 29, 2011 at 11:29AM
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A father and husband suffers a stroke. His family observes the most well-known symptom, seizure, and calls an ambulance. A half hour later the man waits, unconscious, to see an emergency room doctor. Another half hour passes before the doctor can diagnose the seizure as a symptom of stroke. The doctor gives him aspirin to thin the blood. An hour, later there's no change. A series of drugs designed to break up blood clots, the cause of stroke, fail to have any effect. By the third hour, it’s too late. Brain death ensues and the family is left to say goodbyes to a man who cannot hear them.

Over 130,000 Americans and their families fell victim to similar tragedies in 2010. Every day, hundreds of others escape death only to find that brain damage caused by ischemic stroke - a blood clot in the brain - has left them disabled.

SHELTER: A Major Innovation in Stroke Treatment

Two brothers, neurologist Vallabh Janardhan, and Vikram Janardhan, an engineer, found these numbers unacceptable. With support from the National Science Foundation's (NSF) Small Business Innovation and Research (SBIR) program, the Janardhan brother's company Insera Therapeutics Inc. developed SHELTER. SHELTER stands for Stroke Help using Endo-Luminal Transcatheter Embolus Retrieval. The device is an extra-long catheter containing a sheath, which captures and contains blood clots and an internal nickel-titanium filament that breaks up the clots. What makes SHELTER unique is its ability to contain the clot. Current similar technologies run the risk of releasing “blood debris” from the clot, which may travel through the patient's veins only to settle elsewhere and eventually cause secondary strokes.

"At the end of the day, ischemic strokes are simply a clog in a pipe," said Vikram Janardhan. "But such strokes are the leading cause of long-term disability in the United States. We ought to be able to leverage innovative technology to successfully treat this medical emergency."

Personalized Care and Flexible Treatment

SHELTER is quite innovative. It’s not only the first to both capture and break up blood clots, but it’s also the first technology of this kind that can reach the infinitely small blood vessels of the brain. Previous treatment techniques could only treat arterial blood clots. Even more novel is SHELTER's adaptability. Doctors can dial in the diameter and length of an individual patient's blood vessels, providing extremely personalized care in emergencies and increasing the probability of successful intervention.
Greg Baxter of the National Science Foundation, who oversaw the Janardhan brother's research, said, "Blood clots and blood vessels are not all the same size and shape, so a one-size-fits-all removal device is not the best solution. Personalized medicine is driving many new innovations, and Insera's approach follows this trend - they found a way to bring personalization to a potentially powerful treatment approach, and we're proud to have been a small part of this effort."

Current drug-based treatments for stroke rely on aspirin or blood-clot-busting drugs, which are effective only within three hours after stroke. It can often take longer to properly diagnose and treat strokes, and even then the drugs may not be effective. In fact, many clot-busting drugs result in undesirable side effects such as systemic bleeding. The use of devices like SHELTER can extend a patient's window of effective care from three to eight hours. This extended treatment window could save the lives, or quality of life, for thousands every year.

Rigorous Testing in “Worst Case” Conditions

The SHELTER device has been submitted to rigorous testing. The Janardhan brothers simulated emergency situations by creating silicon models of the brain's blood vessels modeled after those found in medical cadavers. The brothers then introduced “severe disease burden” and created veins that more closely resembled those with arterial maladies such as plaque, aneurysms and atherosclerosis. “Disease burden” makes veins more difficult to navigate and treat than working on test animals with good arterial health. Thus, SHELTER has proved itself in environments more burdensome and realistic than normal testing of similar catheter-based devices currently in use.

Pictured Left: SHELTER Testing Stroke
"If widely adopted, the approach could significantly cut animal testing for some medical devices and reduce overall product development costs by as much as ten percent," said Vikram Janardhan. "The silicone replica of the human brain can also be used as a humane alternative to train hundreds of physicians in the use of SHELTER."

Clinical trials for SHELTER are expected to start as early as 2012, with regulatory approval expected soon after.

Pictured Right: SHELTER Test Brain