A tiny clot-removing surgical device that looks like a corkscrew is said to be saving lives at Sacred Heart Medical Center and reducing the level of disability experienced by some stroke victims.


The device, formally called the Merci Retriever, isnt a cure-all, but has significantly improved the outcomes of more than half the nearly 15 stroke victims treated with it here in the past year, claims Dr. Chris Zylak, a partner in Inland Imaging Associates PS, of Spokane.


He says two brain scans show what the device can do. In one, a blood clot has stopped all blood flow into one area of a patients brain. In the other, the flow of blood has been restored after the Retriever has removed the clot. In some instances, Zylak says, You can save the brain tissue and improve the stroke conditions immediately.


Zylak, a neurointerventional radiologist, says, If we didnt perform this procedure, these patients would be severely disabled or die. Im always successful at opening the blood vessel, but that doesnt always equal a positive clinical result if damage has already been done. With some patients you can perform the procedure within the first hour after a stroke and its too late, and with other patients you can get in later than you would have liked and get great results.


Developed by Concentric Medical Inc., of Mountain View, Calif., the Retriever is a corkscrew-type device thats guided into the brain using standard catheterization techniques. A small puncture in the groin is used to introduce the device, attached to a Merci Microcatheter and Merci Balloon Guide Catheter, into the body and maneuver it up an artery that leads to the brain. Once it reaches the targeted area, the Retriever captures and removes the blood clot to restore blood flow.


The balloon is maneuvered up to the carotid artery in the neck, a guide wire and the microcatheter are deployed through the balloon and placed next to the clot, then the Retriever is released from inside the microcatheter. The microcatheter is only about 3 millimeters in diameter, while the plastic-coated Retriever thread is about half that size, says Zylak. He says the Retriever burrows into the clot with a twisting motion, and then, I pull the thread into the microcatheter along with the clot and suck it out of the brain.


The process of using a tiny curved wire to thread such a miniscule device through the groin and up to the neck is called a minimally invasive procedure and, although unheard of a relatively few years ago, is standard practice today.


What happens with the Retriever above the carotid artery, though, is a procedure that was approved two years ago and is much more complex, Zylak says.


Above the neck, Zylak channels the microcatheter, depending on where the clot is located, into either the main branch middle cerebral artery or the basilar artery, the two largest arteries in the brain, he says. From there, the device is guided through vessels to the clot.


He says most Retriever procedures take about one hour, but hospital stays for the patient can be much longer as specialists address the problem that caused the clot in the brain, which often originated in the heart or carotid artery, he says.


Zylak, like Dr. Madeleine Geraghty, a neurologist at Rockwood Clinic, says time is of the essence if any treatment is going to save or lead to a better outcome for a stroke victim.


For the Retriever to be effective, he says, treatment must begin within eight hours of the stroke for patients experiencing an anterior, or frontal, stroke, and within 12 hours of a posterior, or back-of-the-brain stroke. That time differential is explained by the different blood vessels that supply blood to the two parts of the brain, Zylak says.


The Retriever is put into use if drugs fail to dissolve the clot, he says.


Geraghty says clot-busting medicines can be administered intravenously or through a catheter inserted through the groin. An intravenously administered drug is only effective for up to three hours after a stroke, and clot-busting medicines introduced through the groin are effective up to six hours after a stroke, she says.


Geraghty says Sacred Heart recently was selected to participate in an international clinical trial to study Desmoteplace, a clot-busting synthetic derivative of bat spit that could extend the therapeutic window for effective treatment up to nine hours after a stroke.


Zylak says, The Merci Retriever compared to clot-busting medications is like a mechanical device compared to medications, or Liquid Plumber compared to a snake to unplug a drain.


As a neurointerventional radiologist, Zylak is trained to treat every blood vessel in the body with the exception of blood vessels in the heart.


Yet, he says, My primary interest is the brain. Its the biggest need here (at Inland Imaging) and also my personal preference.


In addition to attending to stroke victims, Zylak says he devotes many hours to treating patients with brain aneurysms. A brain aneurysm is caused by a bubble in a blood vessel in the brain. If the bubble ruptures, its fatal 50 percent of the time, he says.


To treat a brain aneurysm, he inserts a catheter through the patients groin, guides it to the brain, then fills the bubble in the defective blood vessel with a ball of titanium thread that stops blood from stressing that weakened wall of the blood vessel. With some successful procedures, the patient is released from the hospital that same day, Zylak says.


Why Spokane


A specialist whose skills are in high demand, Zylak says a primary reason he and his family settled in Spokane is the Inland Vascular Institute, a division of Inland Imaging that was a pioneer in merging vascular surgery with radiology. It was launched in 2000.


I like including vascular surgery with radiology practices, he says. It allows for the best in patient care, rather than focusing on economic factors.


Raised in Ontario, Canada, Zylak says he attended and graduated from the oldest medical school in Canada, Queens University, in Kingston, Ontario. After residencies and internships in Arizona and Florida, he moved to Spokane to work as an interventional radiologist for Inland Imaging in 2003.


In 2004 and 2005, he trained to do inner-cranial vascular work at Oregon Health Science University, in Portland, Ore., where he learned to operate the Merci Retriever device. He rejoined Inland Imaging last September.


Contact Rocky Wilson at (509) 344-1264 or via e-mail at rockyw@spokanejournal.com.