Wow of the week: Blood-sucking robot could save one in 50 of us who will develop brain clot

by Lindsey Alexander, medcitynews.comAugust 10th 2013 8:59 AM

While most surgeons won’t go near a brain clot unless it’s easy to get to (read: on the surface) in fear of further damaging brain tissue, more than 40 percent of patients who have them die within a month.

The active cannula, what Vanderbilt assistant professors Robert J. Webster III and Kyle Weaver call the image-guided surgical device, uses steerable needles to penetrate the brain and suck away those riskier clots.

Webster’s father had a brain hemorrhage, and had been working on a transnasal surgical device. But not just patients and families have dreamed of such a device, of course. Neurosurgeon Marc Simard listed such a then-imaginary device as the active cannula at a conference last year, and Webster was in the audience. He realized he could morph his research to fit Simard’s description almost perfectly. Since then, the team at Vandy has moved quickly.

In simulations, the active cannula had a 92 percent success rate.

According to the press release:

The brain-clot system only needs two tubes: a straight outer tube and a curved inner tube. Both are less than one twentieth of an inch in diameter. When a CT scan has determined the location of the blood clot, the surgeon determines the best point on the skull and the proper insertion angle for the probe. The angle is dialed into a fixture, called a trajectory stem, which is attached to the skull immediately above a small hole that has been drilled to enable the needle to pass into the patient’s brain.
The surgeon positions the robot so it can insert the straight outer tube through the trajectory stem and into the brain. He also selects the small inner tube with the curvature that best matches the size and shape of the clot, attaches a suction pump to its external end and places it in the outer tube.
Guided by the CT scan, the robot inserts the outer tube into the brain until it reaches the outer surface of the clot. Then it extends the curved, inner tube into the clot’s interior. The pump is turned on and the tube begins acting like a tiny vacuum cleaner. . . .

Then it’s rotated out and extracts the tubes.

Eventually, the researchers want to make the model even more accurate. To do that they plan to “add ultrasound imaging combined with a computer model of how brain tissue deforms to ensure that all of the desired clot material can be removed safely and effectively.”