Significant recent innovations in medical technology are enabling physicians to more effectively and safely venture into the blood vessels of the brain to treat patients suffering from an acute ischemic stroke.

At Allegheny General Hospital (AGH) interventional neuroradiologists are the only specialists in the region now using the latest of these revolutionary devices, called the Penumbra Stroke System, which have improved patient outcomes by extending the window of treatment from the standard three hours to as long as eight hours after a stroke has occurred.

Approved by the FDA earlier this year, the Penumbra Stroke System is a novel therapy in which a specialized catheter is threaded to the site of the blood clot through a small groin incision. Under X-ray guidance, a suction device is then used to delicately remove the clot.

“Ischemic stroke is caused by a blockage in a blood vessel that stops the flow of blood and deprives the surrounding brain tissue of oxygen. In the absence of oxygen, the brain cells in the immediate area begin to die and release a cascade of toxic chemicals that threaten brain tissue in the surrounding area, called the ischemic penumbra,” said Ashis Tayal, MD, a stroke neurologist and medical director of AGH’s Comprehensive Stroke Center.

“Current therapy in these types of strokes is often not effective or can be difficult to administer within the critical three-hour treatment window. Clot dissolving drugs have a high risk of bleeding complications, open surgery is complex and time consuming, and the first generation of mechanical clot removing devices have demonstrated some limitations.”

The Penumbra System provides an exciting new alternative for patients and is another example of AGH’s long history of innovation in stroke treatment , Dr. Tayal said.

In 2004, AGH radiologists Andrew Ku, M.D., and Robert Williams, M.D., were the first in western Pennsylvania to use the MERCITM Retriever System, a similar technique in which a corkscrew like device is used to remove blood clots in brain vessels. AGH doctors also helped pioneer the use of low dose intra-arterial t-PA, a procedure in which the blood thinning agent t-PA is administered directly to the site of a blood clot to rapidly dissolve it.

Drs. Ku and Williams are currently among a select group of doctors trained in the use of specially designed stents to keep narrowed brain blood vessels open.

According to Dr. Ku, the Penumbra Stroke System was designed taking into account many of the limitations that have prevented other therapies from working well. “The Penumbra approach brings a whole new concept to stroke treatment that we did not have before, and because clots come in various shapes and sizes, it's extremely important to have a wide array of tools available," Dr. Ku said.

In a study coordinated by Penumbra, Inc., and the Food and Drug Administration that was presented at the 2008 American Stroke Association International Stroke Conference in February, the Penumbra Stroke System was reported to have a higher-than-usual rate of successful recanalization – or restoring blood flow through a blocked vessel, which may result in better outcomes and a lower complication rate.

“Because we attack the blood clot with suction instead of piercing it, we are able to remove clots that would otherwise prove to be extremely difficult with previous techniques,” Dr. Ku explained. “The Penumbra System rapidly restores blood flow to the brain and reduces the amount of neurological trauma caused by the stroke.”

Ischemic stroke is the third leading cause of death in the United States and more than 700,000 people suffer from a stroke every year. It is the leading cause of severe, long-term disability.

Dr. Tayal said it is extremely important that stroke patients be treated at hospitals which are uniquely equipped and staffed to provide them with the complete spectrum of advanced stroke therapies and services around-the-clock.

AGH is certified as a Primary Stroke Center by the Joint Commission and was named a Stroke Center of Excellence in a recent survey of the nation’s hospitals. National studies have demonstrated that patients treated at such centers receive effective diagnostic and therapeutic stroke care more quickly and with better results than those treated elsewhere.

In 2007, AGH open the region’s first dedicated inpatient Stroke Unit that centralizes and coordinates the care of stroke patients by the hospital’s multidisciplinary stroke team. Though still the only facility of its kind in the region, such inpatient programs have been associated with better patient outcomes and are now a Class I Recommendation for comprehensive stroke centers by the American Heart Association and the American Stroke Association.

More than 1,000 stroke patients are admitted to AGH annually, Dr. Tayal said.

Risk factors for a stroke include hypertension, heart disease, diabetes, family history, smoking, obesity, blood clotting disorders and oral contraceptives.

Symptoms of a stroke include sudden numbness in the face or extremities, sudden confusion, trouble speaking or understanding speech, sudden trouble walking, dizziness or loss of balance, or sudden severe headache of unknown cause. Anyone who experiences these symptoms should call 911 for emergency treatment.