By Peter Cameron, Special to the Tribune
January 26, 2011
Most patients facing an operation would of course prefer an experienced surgeon over one just learning the procedure.
But how, then, does a surgical student get the thousands of hours of practice necessary to gain confidence and expertise without putting people at risk?
Increasingly, the answer is being found in virtual simulators. That's especially true in arthroscopy, a type of minimally invasive surgery on joints requiring the insertion of a camera and instruments into holes in a knee or shoulder. Such "closed" operations lend themselves particularly well to virtual simulation, because the real thing is done on a monitor anyway.
Dr. Mike Kremer, co-director of the Rush University Simulation Laboratory in Chicago, likens the simulators — hand grips that appear on the monitor as surgical instruments — to "a very high-level video game."
"If the operator nicks the (simulated) liver, there is bleeding visible on the screen. It's very responsive in terms of various kinds of complications that can occur," he said. "What the operator sees and what they feel is very similar to what they see and feel in the operating room."
The simulators are a luxury surgeons from previous generations couldn't enjoy. Closed surgery had to be learned the old-fashioned way, with a lot of hand-holding on real patients and working on scarce and often expensive cadaver parts.
At the NorthShore University HealthSystem in Evanston, Dr. Howard Sweeney has created the Psychomotor Skills and Virtual Reality Laboratory for medical residents to hone their surgical skills without putting patients in harm's way. The simulators help to solve the old problem with teaching surgery.
"You cannot learn a motor skill unless you do it," Sweeney said. "In other words, you can't learn surgery unless you do the surgery."
At 84, Sweeney is too old to operate, and has been retired from that aspect of medicine for eight years. But having worked at NorthShore for more than 50 years, he still can share his knowledge with younger and steadier hands and help guide them through some of the more difficult facets of closed surgery.
"You're looking at a two-dimensional screen doing a three-dimensional job. That's not easy," he said. "You have no idea of depth perception. That takes a while for people to learn."
The lab contains models as simple as a toy truck inside a small cardboard box, and as complex as the $85,000 insightArthroVR, a brand-new, high-tech surgery simulator that allows the user not only to manipulate a camera and instruments within a shoulder, but also to "feel" the hard and soft tissues in the body, a technology called haptics. For example, the trainee would feel a tool hit a virtual bone and would have to go around it, rather than moving right through it as though it were a ghost.
To gain and maintain the hand-eye coordination needed to perform arthroscopic surgery — which can require two surgeons, three hands and a foot pedal working together, all while having to watch the procedure on a screen — Sweeney and his colleagues emphasize repetition.
"They can literally do these exercises hundreds of times before they actually touch a patient," said Dr. Jason Koh, vice chairman of the Department of Orthopedic Surgery at NorthShore.
The technology is quickly moving toward the ability to do mission rehearsal, said Dr. Stephen D. Small, the director of the Center for Simulation and Safety in Healthcare at the University of Chicago Medical Center.
Just as NASA astronauts sit in a fake cockpit and simulate flying a mission before the real thing, medical professionals will eventually be able to map out a specific individual's body part using MRI and CT scans, and practice the operation virtually before cutting into real flesh. Unexpected complications could also be introduced during rehearsal to keep surgeons on their toes.
Small estimates the technology needed for true surgical mission rehearsal is about 10 to 15 years away.
But as the technology gets better, young surgeons have less time to practice their skills than their predecessors did. Sweeney grumbles about the restrictions medical education governing boards have put on a medical resident's workweek, currently capped at "only" 80 hours, to prevent mistakes from sleep-deprivation. In his day, a young doctor had an unlimited amount of time to practice his skills. And residents now are busy enough that they can't spend as much time as they would like inside the lab and still stay under their 80 hour threshold.
Another tool for residents to practice their hand-eye coordination inside the lab is an actual video game. Sweeney purchased a Wii and a game called Marble Mania, in which residents use the cordless wand to manipulate a marble through three-dimensional mazes. Sweeney said studies have shown that surgical students with gaming backgrounds have a slight head start over those without.
But even the most cutting-edge technology cannot fully replicate the real thing.
"We still don't make people, and we still don't know exactly how they work," Small said.
Virtual surgery simulators are never meant to and cannot be a substitute for the human body, where an infinite number of known and unknown factors can influence the outcome of a procedure. Instead, they are used as another rung on the ladder for young surgeons as they slowly progress from studying anatomy textbooks to eventually working on live patients.
Kashif Ali, an orthopedic surgical resident in his third year of a five-year training period, practices with the Wii in both his dominant right hand and weaker left to improve his ambidexterity and to beat the best times set by his colleagues.
But does he play video games outside of the lab?
"When I was younger I did," he said. "Now I don't have free time really to do much of anything."
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