Parallels are often drawn between the fields of aviation and medicine. It has been said that the number of hospital-related preventable deaths in the United States alone is equivalent to 20 large airplane crashes, with no survivors, each week.
With the advancements made in flight safety, doctors are now looking to the field of aviation to improve patient safety.
“Every pilot that gets in a plane has trained in a simulator and therefore it doesn’t matter what country you’re in, everybody has trained in that simulator. You have to be up to a certain level of efficiency before you ever get in a plane. Everybody who is training in neurosurgery throughout the world could be trained on simulators and everybody could get the exact same level of training,” said Dr. Rolando Del Maestro, director of the Neurosurgical Simulation Research Centre in Montreal.
Since 2007, Del Maestro has been working to develop NeuroTouch, an advanced virtual reality surgical simulation program. The project began with surgeons of all disciplines, but ultimately the team decided to focus on designing a neurosurgery simulator.
Del Maestro said this decision was made for two reasons.
“Errors in neurosurgery potentially had a greater risk to the population,” said Del Maestro. A large focus of the simulation project is patient safety, and reducing the number of neurological deficits suffered by patients was a priority.
Second, Del Maestro explained that the brain is a more complex organ and creating simulated brain tissue would push the boundaries form an engineering standpoint. The brain is a difficult organ to simulate both due to its anatomical complexity and because it pulsates during surgery.
“If the most complex tissues could be simulated, then others could obviously be also,” said Del Maestro.
Funding for the project was received from the National Research Council of Canada in 2008 and the first prototypes were released in 2010. By 2012, NeuroTouch was available for purchase.
Del Maestro explained that the first challenge was to develop a simulator capable of modelling brain tissue and surgical instrument use. Once NeuroTouch was able to simulate these core neurosurgical functions, the next hurdle was to develop different clinical scenarios.
“How do I know the information I’m putting in makes this feel like a real tumor? How do I know that’s correct?” asks Del Maestro. “We’ve taken tumors out of humans and measured the stiffness of them and we put that information back into the simulator. We’ve tried to make it as realistic as we can.”
“The biggest advantage of NeuroTouch is what’s called haptic feedback. You can actually feel your instruments and you can feel yourself doing the operation. The advantage is that NeuroTouch seems to be the most advanced simulator in the world for this property,” said Del Maestro.
The next part of the process was to develop metrics, which measure data collected from the simulator relating to patient safety as well as surgeon efficiency.
“How much tumor do you remove? How much tissue damage was there? How much bleeding do you allow? They’re important because they help you with the concept of safety, efficiency, and they allow you to actually begin the process of thinking about what is the most important thing that you would be involved in doing,” said Del Maestro.
“It can measure absolutely everything you do with both your hands at the same time,” said Del Maestro. This generates an enormous amount of data which scientists at the Neurosurgical Simulation Research Centre have begun to use to examine surgeon performance.
Del Maestro says that more data need to be collected, but in the future, this type of technology could be used to select the most adept students based on objective performance measures. Students could be asked to perform a simulated surgery using NeuroTouch as part of an interview for a residency program, and data collected could give interviewers information about the student’s skill level.
“If you have a particular individual who has exceptional skills, should that individual be fast tracked into parts of neurosurgery that need those technical skills? Can you pick out individuals who have these skills and help them move through more quickly? If people don’t have that level of skill, could you train them up to that level without using an operating room,” pondered Del Maestro.
This type of technology could also have implications for how medical trainees are graded. As Del Maestro pointed out, students are often evaluated through cognitive rather than skill-based exams. Subjective evaluations of their surgical skills may be made, but NeuroTouch would allow examiners to provide objective feedback.
Objective measures of performance may also be useful in evaluating people who need to take time away from their training. Del Maestro gave the example of an individual who takes time away from his or her residency program either for medical reasons or to complete a PhD.
“Is it reasonable that we expect that individual to be just as good as they were before they left? If we know what level they’re functioning at before, we can reassess them after they come back and try to train them up to where they were before. We’ve actually begun to do this with some situations that we run into,” explained Del Maestro.
These metrics also show that surgeons continue to improve, even after their formal training has ended.
“This means neurosurgeons must learn things after they graduate,” said Del Maestro. “They get better after time and that probably has to do with experience. The bottom line is that if you think of how we train residents at the present time, the first time that the resident is using the instruments that we talked about, generally speaking, is on a human being. That’s where the learning occurs.”
He also believes that NeuroTouch could help people become expert surgeons in less time. He said that if people learn more quickly during and after residency, this would maximize the time they are operating at an expert level.
Despite the exciting advancements NeuroTouch has brought to the field of surgery, there have been some challenges in terms of design and implementation.
First, Del Maestro acknowledges that there are ethical issues involved in training some surgeons on simulators and others in a more traditional way.
“Now we have to train people on simulators and prove that they’re better in the operating room. Those are the types of experiments we’re working on now,” said Del Maestro.
In terms of continuing research, Del Maestro and his team have recently submitted a study for publication which examines the effect of acute stress on surgeon performance. This involves simulation of an uncontrolled bleeding event during surgery.
“After you have this acute stress, is your performance better, worse, or about the same,” asked Del Maestro.
Surgeons need to be able to continue to function after the acute stressor has resolved. This type of research would be difficult or impossible to conduct in the operating room.
The final goal to accomplish with NeuroTouch, according to Del Maestro, is patient-specific rehearsal.
Patient-specific rehearsal involves the simulation of pathologies in specific patients, enabling a surgeon to “practice” operating on a patient before the patient even enters the operating room.
To achieve this goal, NeuroTouch must combine information about the patient’s specific tumor type with data obtained from their scans.
“You would do an MRI scan on a patient with a brain tumor. That patient’s information goes into the simulator and you would actually operate on that person’s brain tumor before they go into surgery to see what things would work better and what doesn’t,” explained Del Maestro.
As part of the globalization of NeuroTouch, patient-specific simulations could also let a surgeon consult a colleague in another country about surgical approach.
The main limitation of this type of advancement, at present, relates to computing abilities. Del Maestro said that this type of patient-specific simulation would require a huge amount of data and thus a great deal of computer power.
Despite these limitations, surgical simulation is a growing field which can have implications for patient safety and globalization.
“Everybody who is training in neurosurgery throughout the world could be trained on simulators and everybody could get to the exact same level of training. This would allow for the improvement of neurosurgical ability across the world. The whole world could be linked in one simulation curriculum,” said Del Maestro.