For Halifax-based neurosurgeon David Clarke, the Monday-afternoon surgery session of Aug. 17, 2009, was anything but routine. For starters, his patient’s brain tumour was located in a tricky spot, close to the delicate part of the brain that controls speech. A small slip of the scalpel either way could be disastrous. But despite a few tense moments, the tumour was successfully removed, and an hour later, Clarke was meeting with the patient, Ellen Wright, in her room.
“She asked me a question I’ve never heard before,” recalls Clarke. “‘So how did my virtual brain surgery go?’” Twelve hours later, on Tuesday morning, Wright became the first person in the world to undergo neurosurgery after a computer-simulated dress rehearsal. The tumour was removed successfully, and she was home the next day. By Thursday, she was able to attend the press conference announcing the medical breakthrough.
Clarke, a professor of neurosurgery at Dalhousie University and a member of Halifax’s Brain Repair Centre, is part of the Canada-wide team that developed the new virtual-surgery technique. Using magnetic resonance imaging (MRI), the team creates a computer model of the patient’s brain, then feeds it into an elaborate simulator called NeuroTouch. The surgeon peers at the modelled brain through a microscope, similar to the one in the operating theatre, and performs the “surgery” using virtual tools that are so true to life, they even simulate the pressure of the brain tissue against them.
It’s a realistic sensation, says Clarke. “I can even see the brain pulsating as it normally would. The beauty is that we’re not operating on a generic brain, but on an exact copy of the patient’s brain. By the time we perform the real surgery, we have a pretty accurate idea of the kind of problems we’re likely to run into.”
Developing the virtual surgery has already been a three-year process involving surgeons, radiologists, engineers, software designers and others — a team of 50 people from 10 medical centres and universities across Canada. It was spearheaded by the National Research Council of Canada and supported by funding from the Canada Foundation for Innovation. “The NRC did a beautiful job bringing everyone together and getting us all speaking the same language,” says Clarke. “That was the key to the project.”
While the technique promises improved success rates for complex surgeries, says Clarke, it will also become a powerful teaching tool for students in just a few years. “Neurosurgery involves a lot of highly complex procedures, and until now, rehearsal has been difficult,” he says. “The old model — the one we’ve been using to teach surgeons for more than 100 years — is an apprenticeship model. A student is given a few basic tasks to perform during surgery, and then gradually, more and more complex tasks are assigned.”
Clarke sees this as an outdated model for a couple of reasons: it’s difficult to teach some complex procedures in a hands-on way, and there is an issue with patient safety. The virtual system can also be used in the future to assess a surgeon’s skill. “Right now, we have no way of really measuring the skill level of surgeons in a quantifiable way.”
For now, the virtual-surgery process is expensive and experimental, but Clarke predicts that a software program will be in widespread use on basic computers at teaching hospitals around the world in the near future and that the principles of the virtual system will eventually be applied to other types of surgeries.
“It’s such a valuable tool,” he says. The virtual system allows surgeons to answer questions ahead of time, such as the potential for injured tissue in a given surgery. It also allows surgeons to predict the dangers involved in a surgery and to practise the more complex aspects of the procedure ahead of time.
“And there’s another nice thing we don’t have in the real operating room,” he adds. “A reset button.”
The CFI factor
The landmark virtual brain surgery first performed by doctors in Halifax is just one of the neuroscience initiatives made possible by the new Life Sciences Research Institute and its Brain Repair Centre — research dedicated to disorders such as Parkinson's, Huntington's, Alzheimer's, amyotrophic lateral sclerosis (ALS), multiple sclerosis and a host of other neurological problems. The state-of-the-art institute in the heart of Halifax was made possible in large part thanks to a $5.5 million grant from the Canada Foundation for Innovation — the largest grant ever awarded to medical researchers in Atlantic Canada.