It's like Elmer's Glue, Silly Putty, or the spongy middle of a brownie. It's not a child's toy, but the latest tool for a new breed of doctors trying to fix life-threatening conditions in the brain without brain surgery.
The new substance, Onyx HD500, is a liquid that can be used to treat an aneurysm, a weak spot in a blood vessel that balloons.
Such aneurysms can be deadly if they burst, and they are hard to treat without damaging the brain or critical blood vessels. Doctors inject Onyx into the aneurysm, where it quickly solidifies, cutting off the area's blood supply.
The doctors using such tools go by the lengthy label "neurointerventionalists." Just as interventional cardiologists brought new techniques a generation ago, replacing open-heart surgeries with stents to open arteries, these doctors bring minimally invasive techniques to the brain.
"It's such a relatively new field that it's very hard for people to understand it — that you can take a very small catheter and snake it into the brain," said Dr. Nasser Razack, director of interventional neuroradiology at Bayfront Medical Center in St. Petersburg.
Razack has a simpler way of telling people his job. He calls himself a "plumber for the brain."
At Tampa General Hospital, Dr. James Lefler explains it like this: "I'm like a cardiologist, except instead of going to the heart, I go to the head."
Razack and Lefler, Tampa General's director of neurointerventional radiology, are among about 300 such specialists in the country. The field is so young that a national group representing such doctors just held its first independent yearly conference in 2004.
But the group is rapidly finding new ways, like Onyx, to treat brain disorders. Neurointerventionalists are pioneering treatments for stroke that include injecting drugs and using tiny tools to remove blood clots. The doctors also have developed other ways to treat aneurysms and tangles of blood vessels in the brain that cause seizures and headaches.
Their chief weapon is the microcatheter, a tiny tube that can be inserted into a blood vessel and guided to the brain, where it can be used to inject dye or drugs, inflate a balloon or pop out a tiny space-age tool.
The field has completely changed in the relatively short time since Dr. Robert Tarr, who will soon become president of the Society of Neurointerventional Surgery, did his fellowship training in the late 1980s.
"Back then, there weren't many things we were treating for a cure," Tarr said. "We were treating things to make it easier to treat with other methods."
One of the most common treatments was using catheters to help cut off the blood supply to tumors or tangled vessels so surgeons could remove them more safely.
Now, neurointerventionalists often take care of such tangles themselves.
'Worse and worse'
A year ago, Indian Rocks Beach resident Jan Baldwin noticed a sharp pain shooting through her head when she bent over. Then when she coughed or sneezed. If she lay her head flat, without a pillow. If she lifted her legs at the same time.
"It just got worse and worse," she said.
Baldwin, 66, had an aneurysm behind her right eye.
The oldest — and still the best option for most patients — would be surgery, clipping the aneurysm off from its main blood supply. Next would be a treatment that neurointerventionalists use: filling the space with coiled wire, so it would clot.
"Our goal is to disconnect the aneurysm from the parent circulation," Razack said.
But Baldwin was leery of brain surgery. And the shape of her aneurysm — the neck, or spot where it joins the main blood vessel, is wide — meant that it would be hard to fill with coils.
Instead, Razack offered to fill the aneurysm with Onyx. He would block the aneurysm off from the main blood vessel with a balloon, then inject liquid Onyx in small doses. As it solidified, it would fill the aneurysm so it could no longer rupture.
Razack has used Onyx on 10 patients. As one of three Florida doctors using Onyx, he has been asked to present his results at a forthcoming national conference. Elsewhere in the Tampa Bay area, Tampa General will soon be using Onyx and St. Joseph's Hospital is looking into it.
Right now, only a handful of neurointerventionalists practice in the Tampa Bay area. But it's a growing field, treating conditions that once required brain surgery — or couldn't be treated at all.
Pain has stopped
Baldwin didn't know any of that when she decided to have Razack treat her aneurysm with Onyx. The treatment has some risks: The Onyx could travel to the wrong place, or the blood vessel could rupture during treatment. Razack and other doctors caution that while Onyx is a good treatment for some aneurysms, surgery remains the most reliable choice.
But Baldwin's operation was a success. The pains in her head have gone away, and she's more interested in other issues, like going to watch her granddaughters water-ski. She has started driving again. And she has a new appreciation for the most mundane pastimes.
"They didn't guarantee it would stop the pain, but it has," Baldwin said. "Now I'm actually scrubbing my shower floor. I like getting back to doing my own cleaning."
Lisa Greene can be reached at firstname.lastname@example.org or (813) 226-3322.