Chapel Hill, N.C. — When a person is having an acute stroke, every minute of delayed treatment means a higher risk of permanent brain damage. A new procedure, available at UNC Hospitals, hopes to increases a person’s window of treatment up to eight hours.

A stroke is caused when a blood vessel that carries oxygen and nutrients to the brain is either blocked by a clot or bursts, according to the American Stroke Association (ASA). When the vessel is blocked, part of the brain cannot get the blood and oxygen it needs, so it starts to die.

Within eight hours of symptoms, a MERCI (Mechanical Embolus Removal in Cerebral Ischemia) retriever can be used to remove blood clots from the brains of people suffering strokes. The device is a tiny corkscrew sent to the brain through a catheter to remove the clot.

UNC Hospitals is one of only a few hospitals in the state offering a new catheter procedure – Penumbra – to reach even smaller brain vessels.

“By using that we can basically suck out a clot from the brain and restore normal blood flow,” said Dr. Sten Solander, an interventional endovascular neurosurgeon at UNC.

Solander and UNC neurologist Dr. Souvik Sen can spot a blockage with a special CT Scan. Sen said the machine will show an abrupt cut off to the right side of the brain.

With X-ray guidance, Solander sends the Penumbra catheter tip to the blockage point. Similar to a straw, an exterior vacuum pump traps the clot and pulls it out.

“This is after the procedure where we have revascularized and opened up the normal blood supplies,” Solander said, pointing to an x-ray that shows restored blood flow in the brain.

While the MERCI retriever is only effective in half of all patients – with a 20 percent recovery rate. In clinical trials, Penumbra was effective in 80 percent of patients – and had a 50 percent recovery rate.

“It is huge. I do not think we've had another treatment show such a huge impact in reversing the stroke disability in the early stages,” Sen said.

Penumbra is available at UNC, Duke, Moses Cone Hospital in Greenboro and Mission Hospital in Asheville. WakeMed plans to make it available in June.

Despite the new technology that extends the window of treatment time, getting to the hospital as soon as possible is still recommended.

A simpler procedure to prevent permanent brain damage – a clot-busting drug called tPA – can be administered if the patient arrives within two hours of the first symptoms. It takes another hour to see if the injection will help. Generally, only 3 to 5 percent of those who suffer a stroke reach the hospital in time for this treatment, according to the ASA.

Symptoms of a stroke include numbness or weakness on one side of the body, sudden vision loss, a headache and slurred speech. People experiencing symptoms of a stroke are urged to call 911.