A new magnetically-assisted remote-controlled catheter (MARC) allows physicians to better visualize and evaluate brain tissue while treating a stroke, according to a study released at the annual Society of NeuroInterventional Surgery meeting.

The standard way that physicians assess the tissue is by manually maneuvering the catheter and visualizing its progress with X-ray guidance. But the researchers at the University of California set out to investigate if MARC with MR guidance can maneuver through complex vessel anatomy and help the physician see the tissue better.

"Because it's an MR-based modality as opposed to an X-ray-based, you get all the benefits of the visualization capabilities of MR while being able to navigate the catheter itself," Alastair Martin, one of the researchers of the study and professor of radiology at the university, told DOTmed News.

For the study, the researchers sought to determine the average procedure times and how successful a MARC prototype guided by MR is, compared to a manually-navigated catheter guided by MR and X-ray. Each procedure they performed used a cryogel vascular model that simulates the main and branch blood vessels in a human body.

They found that MARC is clearly visible with MR guidance and successfully completed 192, or 80 percent, of the 240 total turns around blood vessels. The manually-directed catheter with MR guidance completed 144, or 60 percent, of the 240 total turns and with X-ray guidance it completed 119, or 70 percent of the 160 total turns.

Additionally, MARC was faster than the manually-directed catheter with MR and X-ray guidance. MARC has an average procedure time of 37 seconds per turn and the manually-directed catheter guided with MR had a 55 second per turn procedure time and a 44 second per turn procedure time with X-ray.

They also looked at how much time it look to navigate the 45, 60 and 75 degree branch vessel angles and they found that MARC was faster than the manually-directed catheter with MR guidance.

Since the success of neurointerventional stroke treatment depends on how fast and accurately the physician can break down the clot and restore blood flow to the affected portion of the brain, MARC with MR guidance would lead to more successful treatments than the standard manually controlled and X-ray guided approach.

"It would allow you to more accurately assess the tissue at the point of stenosis and in the territory downstream from the point of stenosis," said Martin.

If a physician is trying to break down a clot, they need to know whether the tissue downstream is properly diffused and if it's still alive, and MR allows them to do that, whereas X-ray based techniques don't, said Martin.

Other than a faster and more accurate procedure, it provides another benefit for the patient. "It would allow you to prescribe just the appropriate amount of dose to achieve revascularization as opposed to too much or too little," said Martin. "There are potential downsides to too much as well as providing too little for this clot-busting therapy."

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