A New Tool Lets Brain Surgeons See What They're Doingby
Doing almost anything with your eyes closed is usually pretty hard. Now consider that until recently neurosurgeons performed operations without being able to see their patients’ brains. Most still do, but now a Memphis (Tenn.)-based company called MRI Interventions is working to end the “poke and hope” practice. Its technology, ClearPoint, provides real-time brain imaging and step-by-step guidance and is already in use in 21 U.S. hospitals, including the Memorial Sloan-Kettering Cancer Center.
Typically, brain surgery goes something like this: Neurosurgeons obtain images of a patient’s brain, locate the problem area, and plan how best to access it. Then they cut away a portion of the skull and go to work. “The worst thing is the patients often have to be awake during these brain surgeries so they can provide feedback,” says Kim Jenkins, chief executive officer of MRI Interventions. “It’s not painful, but it’s still very disturbing—and these procedures can go on for six, eight hours.”
When neurosurgeons use the ClearPoint system, and can actually see what they’re doing, Jenkins says operation times are cut by as much as two-thirds, and patients don’t have to remain conscious.
During an operation, the patient lies inside the MRI machine, which sends brain images to a monitor on which surgeons then pinpoint their neurological target. ClearPoint software then maps out an ideal access trajectory from the surface of the skull to that target. It also highlights brain areas to be avoided, such as blood vessels.
A “smart grid,” which is affixed to the patient’s scalp, provides precise coordinates for where to enter the skull. Once a hole has been made, a “smart frame” gets attached, which has built-in, hand-controlled tools that allow the surgeon to enter and navigate the brain. Before beginning the procedure, new MRI images are taken to make sure the brain has not shifted. The system has been used, for example, to deliver drugs directly into tumors, ablate diseased tissue using lasers, and place electrodes that help treat neurological conditions like tremors or Parkinson’s disease.
MRI Interventions first started working on ClearPoint back in 2003 and, with the help of $80 million in funding, had a finished product by 2010. The company, which went public last year, makes $130,000 on each system sold, and earns a great deal more over time on disposable components, which cost roughly $7,300 per operation.
As for using the technology, it’s probably no more difficult than operating blind. University of California, San Francisco professor Paul Larson, a neurosurgeon who’s been performing brain surgeries since 1995 and using ClearPoint since 2010, says surgeons tend to pick it up pretty quickly. “We showed [one of our residents] how it worked and had him do a procedure immediately after I’d done one,” he says. “It was fairly discouraging because I’d done hundreds of procedures like this and I thought I was fairly good, but I was only four minutes faster than he was.”