Magnet lets brain surgeons work without a drill

WASHINGTON -- Dr. Demetrius Lopes snaked a thin wire with a tiny magnet on its tip into an artery in Paul Kelsey's groin and threaded it all the way up into his brain.

Aided by a helmet-shaped magnet hung over Kelsey's head, Lopes guided the wire through twists and turns deep in the brain, finally reaching swollen blood vessels that were giving the Chicago man double vision. A few squirts of glue to seal off the excess blood flow, and Lopes pulled the wires back out -- surgery done.

Normally, curing Kelsey's disorder would require operating through a hole drilled in his skull. But doctors now are creating ways to fix brains from the inside, no drilling required. And using magnets as a guide, while still highly experimental, could let them go into deeper, trickier areas than ever imagined to treat aneurysms, strokes and other serious brain ailments.

Poised for shift

Indeed, neurology may be poised for a shift as important as cardiology had years ago when heart specialists began using balloons instead of bypass surgery to unclog heart arteries.

The field is called endovascular surgery, operating by snaking through blood vessels. It's not as easy in the brain as in the heart. Brain blood vessels are smaller and more twisted. Plus, they float in brain fluid that makes pushing wires through them like operating inside a bowl of gelatin.

Bend the wire the wrong way and miss the brain target, and the doctor must pull out the wire -- it can stretch more than 6 feet -- and start over. (They start from the groin, not closer to the head, because it provides a wide, easy-to-thread artery.)

There are only 300 endovascular brain specialists in the country, compared with about 6,000 traditional brain surgeons.

"The reason there are so few doing what we do is it's hard and dangerous," says one endovascular specialist, Dr. Christopher Moran of Washington University in St. Louis, which pioneered research on the magnet guide.

Experiments to prove if the magnet, Stereotaxis Inc.'s Telstar system, works in the brain are under way at Washington University and Rush-Presbyterian-St. Luke's Medical Center in Chicago. While the experiments will take several years, there's optimism because the Food and Drug Administration recently approved the Telstar's use by heart specialists to map the source of irregular heartbeats. In the heart, the system seems to speed up those doctors' work.

In the brain, even smaller Telstar wires "may extend our reach to treat lesions considered untreatable today," says Dr. Joel MacDonald of the University of Utah, who is monitoring the technology for the Congress of Neurological Surgeons.

Take Kelsey, a roofer who suddenly developed double vision whenever he looked down. Brain scans spotted a fistula, a mass of malformed blood vessels that were swelling and putting pressure on crucial vision nerves. Last spring, Lopes, a Rush neurosurgeon, snaked a catheter with repair glue to the spot. But the fistula was too deep and twisted for Lopes to manually push the catheter to its origin, and the swelling returned.

Last month, Lopes tried again with the Telstar. Following his route on an X-ray, Lopes used the magnets like a steering wheel: To navigate twists and turns, the doctor increased or decreased current flowing from superconducting magnets hung over Kelsey's head to the magnet-tipped guidewire in his artery.

This time, the wire successfully pulled a catheter to the fistula's core, giving Lopes a tunnel through which to squirt healing glue. If the three-hour procedure worked, Kelsey's vision should return to normal in six months; he claims a small improvement already.

The magnet's use may not just be for inside blood vessels. Even drilling through the skull doesn't always allow neurosurgeons to reach just the brain tissue they want without damaging nearby spots. Researchers also are studying whether the magnet guide could provide more precision in those cases, possibly helpful in treatment of Parkinson's disease or brain tumors.

As for no-drill treatment, it is a controversial field, not around long enough yet for endovascular fixes to have proven as durable as open-brain methods.

But more patients each year seek no-drill treatments. If the magnet system ultimately is proved to fix deeper, more complicated problems, "what's going to drive it is the public," says Moran. "Most people would rather have us work through the vessel than have their head opened."

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EDITOR'S NOTE -- Lauran Neergaard covers health and medical issues for The Associated Press in Washington.