When it comes to describing brain tumor surgery, David Donahue, MD, is apt with metaphors. “It’s like using a 9-iron to drive a golf ball off your daughter’s nose and trying to hit it as far as you can,” says Donahue, director of neurosurgery at Cook Children’s Health Care System in Fort Worth, TX. “You have misgivings about swinging too hard. That’s what brain surgery is like. You want to know how to safely remove a tumor, and you need to know the best trajectory.”
These days, during tumor removal procedures, Donahue has advanced imaging technology to help him on both accounts. Earlier this year, Cook Children’s deployed an intraoperative MRI unit, which can give surgeons a real-time picture of the patient’s brain during delicate tumor resection procedures. Suspended from the ceiling, Cook Children’s 6-ton, 1.5 Tesla iMRI unit from Imris can swing into action at the surgical team’s behest. Even though surgeons may think they have removed an entire tumor, without a real-time brain scan, it can be difficult to be certain, Donahue says. “It is hard to believe that a surgeon with 20 years of experience is looking inside someone’s brain and can’t tell what is going on, but it is possible. It is good to have fresh information.”
Providing neurosurgeons fresh information is what iMRI technology is all about. Once the domain of research-oriented academic medical centers when it was introduced more than a decade ago, iMRI technology is now working its way into the mainstream. Doing magnetic resonance imaging during surgery, however, raises a number of patient safety issues. In addition, the units are expensive, and installation may require an infrastructure overhaul. But with advances in technology, hospitals are able to turn their intraoperative units into dual-purpose workhorses, capturing regular diagnostic images when no surgeries are being conducted. Work through these hurdles, physician experts say, and the rewards of capturing brain images during surgeries can easily off-set the risks. It’s a tool that can help patients avoid return surgeries.Matured technology
Figuring out surgical logistics around bulky MRI machines has curbed the growth of the technology in the OR, says David Sklar, MD, senior manager of healthcare practice at BearingPoint, a McLean, VA-based consulting company. “The quality of the image depends on the strength of the magnet,” he says. “The lower-field magnets do not produce the quality, but they have more space for the surgeons.”
After waiting for iMRI technology to mature, Rochester, MN-based Mayo Clinic deployed a unit this past January. Three big considerations kept the renowned clinic from embracing intraoperative imaging sooner, says John Huston III, MD, professor of radiology at Mayo Clinic College of Medicine. “Image quality was not as good as we felt it needed to be to make the move into intraoperative,” he says. “OR logistics and patient safety were the other issues.” Mayo’s new 1.5 Tesla unit from GE Healthcare provides high-quality images, Huston says, and does not interfere with the surgical team’s traffic patterns.
That’s in part due to Mayo’s own engineers. They helped to resolve patient safety issues by designing a two-step procedure for moving a patient from the surgical table into the imaging unit’s field. Earlier iMRI models, Huston explains, required that patients move three times, from the OR to a transport gurney to the imaging unit. In Mayo’s configuration, the patient rests on a platter on the OR table, which then slides to the MR reading station. Mayo uses its iMRI unit during brain tumor procedures and placement of deep brain stimulators, a technique used to treat Parkinson’s disease. Despite iMRI’s potential to assist surgeons during these procedures, Mayo was cautious in adopting it. Technology for technology’s sake does not fly, Huston says. “Medical care cannot just be about adopting one new technical advance without proving it is improving care,” he says.Safety’s sake
Adopters of iMRI say that because the technology affects so many areas, the debate over safety can become complicated. “Getting everybody in one room is the hardest part—there are so many different departments involved,” says Jessica Joy, neurosurgery coordinator at Cook Children’s. The hospital formed a safety committee as the $9.7 million project was in the works. With some 20 members, the group spanned more than half a dozen clinical departments, including radiology, surgery, anesthesiology, infection control and risk management, Joy recalls.
The safety committee had to balance competing interests. The most difficult decision, she says, pertained to surgical instrumentation and equipment. Non-magnetic titanium instruments, for example, upheld iMRI safety issues, as they would not be sucked into the powerful magnet. But titanium surgical tools are expensive and offer a very different feel for surgeons. Cook Children’s opted for standard metallic surgical instruments but had to devise in-depth safety procedures to accommodate them.
To boost patient safety, Mayo also adjusted its OR suite to accommodate intraoperative imaging. It added a wireless anesthesia system to use during procedures, Huston says. The wireless system gives anesthesiologists more flexibility in where they work during the case, he says. At Mayo, radiologists are not present during surgeries but can view the MRI images remotely through a picture-archiving system if they are needed to advise, Huston says.
Mayo also configured its OR suite to enable regular diagnostic imaging with the MRI unit when no surgeries are being conducted. This dual-purpose approach makes the economics of iMRI technology more palatable, says Sklar.
But some early adopters of iMRI use their imaging units exclusively during surgery. Cleveland Clinic, for example, has been using a low-field iMRI from Odin Medical Technologies during brain procedures for nearly five years, says Michael Phillips, MD, head of imaging sciences. The single-purpose unit is set up specifically for head imaging and brain surgeries, Phillips says. In 2008, however, the clinic plans to unveil a 1.5 Tesla unit that will be used during surgeries and for diagnostic imaging as well. “That’s where this technology is headed,” Phillips says.
Despite the potential of iMRI, the technology is not for everyone, cautions Donahue, the pediatric neurosurgeon. “Before a hospital invests, it needs depth in diagnostic imaging, nursing and neurosurgery,” he says. “Sometimes hospitals get ideas [about incorporating advanced technology], or a family will ramrod an idea down their throats—when Aunt Bessie leaves $50 million for a bone tumor program and the hospital gets dragged into doing it. If that happens with iMRI, the instrument will sit unused. The hospital must decide if its neuroscience department is strong and willing.”Gary Baldwin is technology editor of
HealthLeaders magazine. He can be reached at firstname.lastname@example.org.