New work from the University Hospital Munich in Germany and New York Presbyterian Hospital has found that use of a “high-fidelity” simulator can greatly enhance soft tissue, bone, bleeding, and dura management and surgical skills for MIS lumbar spine surgery.
Their work, “Use of a High-Fidelity Training Simulator for Minimally Invasive Lumbar Decompression Increases Working Knowledge and Technical Skills Among Orthopedic and Neurosurgical Trainees,” was published in the February 2022 edition of the Global Spine Journal.
Study co-author Ibrahim Hussain, M.D., Assistant Professor in the Department of Neurological Surgery Weill Cornell Brain and Spine Center, explained the style of simulation to OTW: “Soft tissue is simulated by using elastic polymers to give the resistance and consistency of human skin and muscle. The simulated bleeding and cerebral spinal fluid utilize a pressurized air motor and an integrated tubing system to allow diffuse ‘bleeding’ when the soft tissue is dissected.”
“The bleeding can arise from the muscle, epidural space, or cancellous bone, as would be encountered during live surgery, and the volume of bleeding can be controlled based on the level of difficulty the user is trying to experience. The cerebrospinal fluid simulation does not activate unless the dura is injured. The bony portion of the model is made of proprietary materials but very closely approximates the consistency of bone and is excellent for practicing drilling or placing pedicle screws.”
And was there anything that the model could not simulate?
“Currently the primary limitation of the model is the one-level nature of the pathology,” Dr. Hussain told OTW. “The model is based on an actual patient’s imaging from L4-5 stenosis or spondylolisthesis. Therefore, replication of the pathology at the upper lumbar levels where anatomy may be different and more challenging, is not possible at the moment.”
“Also, in real situations, many patients require 2- or 3-level minimally invasive surgeries to treat multi-level degenerative disease. This requires the surgeon to appropriately plan decisions, muscle dissection, drilling, and screw placement more carefully, which is not possible with the current iteration of this model.”
Dr. Hussain also described the pace of improvement, specifically, the speed with which students were able to avoid skipping steps. “We saw a stepwise decrease from the first to the third trial, and I suspect that if we did two additional trials (5 total), we would have seen 0 skipped steps. As with any task, it’s all about repetition and cementing the steps in a logical order that can be replicated almost without a second thought. Once the steps are cemented, then the trainee can begin to focus more attention on the quality of their work. This was my biggest takeaway from this data.”
Dr. Hussain worked alongside Roger Härtl, M.D., the Hansen-MacDonald Professor of Neurological Surgery at the Weill Cornell Brain and Spine Center.
“There is no doubt,” said Dr. Hussain, “that this is the future of surgical training and can potentially be complemented with virtual reality-based technologies. Dr. Härtl and I have also recently been awarded funding from AO Spine North America to study if these trial runs on a state-of-the-art model actually translate into the operating room on live patients, as demonstrated by increased safety and efficiency of senior residents and fellows.”
“This paradigm shift in demonstrating performance in a safe setting before attempting to apply techniques on a patient (as has been the surgical training model for decades) can then potentially be expanded to other minimally invasive surgeries including fusions and endoscopic approaches, which our group is also looking into for rigorous evaluation later this year.”
