“The said doctor can easily practice upon a page and, if he does well, he can use his remedies on my son.” Attributed to Catherine De’ Medici (1519–1589).1
Simulation—An Accepted Tool for Improving Clinical Performance
The concept of a physician ‘practicing’ his or her craft is an ancient one—perhaps even pre-dating the time of Hippocrates. Over the millennium, much has changed in the practice of medicine, but what has not changed is the concept of improving one’s skills. In recent years, the use of digital simulation has been introduced into medical training as a tool for enabling physicians to acquire, improve, and sustain complex skills without using a patient as a training device—a concept that would have probably been appreciated by Catherine De’ Medici’s page.
Today there are a number of companies producing medical simulations, including the Simbionx ANGIO Mentor™. Their use is becoming so prevalent that there is even a medical professional society—the Society for Simulation in Healthcare—whose mission it is to “…lead in facilitating excellence in (multispecialty) healthcare education, practice, and research through simulation modalities.”2 A number of mainstream medical professional societies and boards such as the American Board of Internal Medicine (ABIM), the American College of Surgeons (ACS), the Accreditation Council for Graduate Medical Education (ACGME), the American College of Cardiology (ACC), the Cardiovascular and Interventional Radiological Society of Europe (CIRSE), and the Society for Cardiac Angiography and Interventions (SCAI), to name a few, all have various levels of activities, policy statements, and programs in place to facilitate the integration of medical simulation into curricula. The question is no longer ‘should we use medical simulation?’ but ‘how should we use medical simulation?’
Simulation-based Rehearsal as a Performance Improvement Tool
Medical simulation is often used as a tool to assist a fellow or resident to practice performing a given procedure to improve proficiency. This is generally carried out either under the guidance of a mentor, with performance feedback provided by the mentor, or in a self-directed mode, with self-assessment coming from the learner supplemented with performance data provided by the simulation. Within the past few years, the term ‘rehearsal’ has begun to appear in the medical literature as one of the ways in which medical simulation can be used to improve clinical performance. Webster’s Online Dictionary defines ‘rehearsal’ as “…a form of practice: repetition of information.”3 Educational literature describes rehearsal as a process that facilitates the storage and recall of skills and information through the process of repetition.4 When rehearsal is conducted in a meaningful way, it becomes a powerful tool in learning (a change in behavior) and subsequent performance. The effectiveness of rehearsal as a process for learning is significantly enhanced when the learner is able to understand the relationship of newly acquired information and skills to previously acquired information and skills, and when the learner is able to recognize and generate a correct response to environmental sensory cues.5
The relevance of environmental sensory cues during learning and subsequent performance (particularly of procedural tasks) is well established and has been demonstrated in a number of experiments over the years. For example, Robertson and Pascule-Leone demonstrated that “… learning is enhanced when multiple sources of sensory information cue consistently and simultaneously for the same response.”6 Regarding the results of their experiments, they further concluded that “…these results suggest that a fundamental neural algorithm is responsible for acquiring knowledge about a temporal sequence of responses rather than forming an associative relationship amongst stimuli.”6 In other words, multiple sensory cues occurring in the appropriate order are important for learning procedural tasks. Virtual reality-type simulations (such as the Simbionix ANGIO Mentor), in which visual, auditory, and tactile cues are replicated, are uniquely equipped to create this learning environment.
The positive impact of physically practicing a psychomotor skill in procedural performance has been the subject of a number of other studies. In a classic meta-analysis conducted by Druckman et al. for the US National Research Council, it was concluded that “the research generally indicates that mental practice accounts for about half a standard deviation in performance gain over what is observed for controls. When mental practice is examined for motor tasks having significant cognitive components, or when it is combined with physical practice, the performance gains are much greater.”7
Interest in using medical simulation for rehearsal has reached such a point that the ACGME dedicated its December 2005 ACGME Bulletin to simulation and rehearsal, and in the Executive Director’s column of that issue, Dr David Leach said, “…Healthcare is one of the few high-risk industries that does not conduct routine rehearsals and debriefings. Simulation allows actions to be planned, studied, and debriefed—it enables safer care.”8
Procedure Rehearsal—Maximizing Performance for the Next Procedure
‘Mission rehearsal’ is a term borrowed from the military. It is a specialized form of rehearsal that focuses on a specific operation or task. It not only has the training component of any rehearsal or practice, it also has a planning component. As the US Army Field Manual explains, “Rehearsals allow subordinate units and leaders to analyze the tactical plan to ascertain its feasibility, its common sense, and the adequacy of its C2 (command and control) measures before it is too late.”9 Mission rehearsal—generally referred to as procedure or procedural rehearsal in medicine—combines the performance improvements of a standard rehearsal with the benefits of evaluating an upcoming task. This then facilitates the anticipation of possible courses of actions and reacting accordingly. Properly done, it becomes the ultimate preparation for successfully performing a task, for both the individual and the team.
Simbionix PROcedure Rehearsal Studio—Realtime Procedure Rehearsal for Carotid Stenting
The Simbionx USA Corporation, a US-based company that produces a wide range of virtual reality medical simulations, has recently commercialized an innovative, patient-specific simulation product that is currently available for carotid stenting. This product, the Simbionix PROcedure Rehearsal Studio™, accepts a patient’s computed tomography angiography (CTA) and magnetic resonance imaging (MRI) scan data from either a CD or local picture archive and communication system (PACS) server.10 It then generates a digital 3D model of the patient’s clinically relevant anatomy from the scan data. When this model is imported into the Simbionix ANGIO Mentor, the result is a simulation containing a model of the patient’s anatomy that replicates the visual, auditory, and tactile aspects of the carotid stenting procedure for that particular patient. It enables hands-on practice of all aspects of the procedure, including angiography and stenting, balloon and embolic protection device selection, and insertion, placement, and deployment. Figure 1 is a screenshot of the PROcedure Rehearsal Studio software showing an example of how CTA data from a patient are converted into a simulation model.
A revolutionary aspect of the Simbionix PROcedure Rehearsal Studio is that the process of importing a patient’s CT data into the simulation can be easily accomplished by the clinician or assistant using Simbionix’s proprietary modeling software. This ability to rapidly create a simulated case from actual patient data not only supports procedure rehearsal for that particular case, but also has the potential to create an unlimited library of simulated carotid stenting cases for training and analysis. This effectively indefinitely extends the utility of the Simbionix ANGIO Mentor as a training device.
Comments, Studies, and Expereiences Regarding Simbionix ANGIO Mentor and PROcedure Rehearsal Studio
A number of researchers have conducted studies on the opinions or experiences of interventional cardiologists, interventional radiologists, and vascular surgeons regarding their use of the Simbionx ANGIO Mentor and PROcedure Rehearsal Studio. A few of these are summarized below.
During a live broadcast at the Transcatheter Cardiovascular Therapetuics (TCT) 2006 Annual Conference in Washington, Dr Bill Gray of Columbia University and his catheter laboratory team successfully performed a carotid intervention. What made this live broadcast unique was that one day earlier Dr Gray had practiced the procedure on a Simbionx ANGIO Mentor and PROcedure Rehearsal Studio using a simulated model of the patient’s anatomy. During the live broadcast, the team said they believed that as a result of the patient-based training they used less contrast and less X-ray time and, most importantly, were able to improve patient safety.11 During the discussion after the procedure, Dr Giora Weisz, an interventional cardiologist from the Cardiovascular Research Foundation (CRF) and Columbia University Medical Center, stated, “I believe patient-based simulation can significantly improve patient safety by training physicians on the patient’s own anatomy and by practicing with the appropriate devices before the actual procedure, resulting in shorter procedure time, less unnecessary equipment, and, ultimately, higher success rates and fewer complications.”11
In October 2008, Hislop et al. of the University of Rochester Medical Center presented the results of a face validation study of the PROcedure Rehearsal Studio to the New England Society for Vascular Surgery (NESVS). Their objectives were, “To determine whether a patient’s specific carotid anatomy can be modeled using CTA on an endovascular simulator and whether pre-operative patient-specific case rehearsal accurately predicts operative experience.”12 In their report, the researchers concluded that “…the surgeons strongly agreed (median score 5/5) that the simulation improved the operative flow, increased patient safety and efficiency of instrument use, assisted in the selection of EPD, stent, diagnostic catheter and balloon, decreased overall operative and fluoroscopy time and the amount of contrast used, and that the operative and simulator outcomes were similar. They agreed (median score 4/5) that the simulation assisted with vessel access and with wire selection. Face validity was excellent, and surgeons strongly agreed that the simulator was easy to use, realistically replicated reality, produced realistic imaging and tactile feedback (haptics), realistically replicated patient arch, carotid, and lesion anatomy, and accurately predicted stent dimensions. All simulated EPD, stent, and balloon dimensions matched those used in the operating room. Subjective observations suggested that the simulation predicted difficulty with vessel cannulation but did not accurately model post-stent deployment changes in bifurcation angulation.”12 The researchers concluded that, “These data indicate that patient-specific computed tomography angiogram (CTA)-derived data can be converted to an endovascular simulator with high face validity. We suggest that case rehearsal prior to an operation may be useful in the planning and execution of carotid artery intervention.”12Figure 2 shows images used by Hislop et al. to demonstrate the similarity between the simulated and real angiograms.
Ongoing and Planned Studies Regarding PROcedure Rehearsal Studio
The Department of Biosurgery and Surgical Technology at Imperial College London is conducting research in the field of procedure-specific endovascular virtual reality simulation. The research focuses on examining whether patient-specific rehearsal of a carotid artery stent (CAS) procedure has an influence on the attitudes of physicians toward endovascular tool selection and the use of fluoroscopy. Results of this study will be presented at the June 2009 Annual Meeting of the Society for Vascular Surgery (SVS) in Denver. Further research will involve examining whether procedure rehearsal has an influence on the technical and team performance of a CAS procedure, and how this technological advance can be integrated into the daily interventional practice.
The lead researcher for this study is Professor Nick Cheshire, who is Head of Circulation Sciences and Renal Medicine at Imperial College Healthcare in London, and who founded the European Virtual reality Endovascular RESearch Team (EVEREST) group. This group involves three academic centers (Imperial College Healthcare, London, University Hospital Ghent, and Sheffield Vascular Institute) and includes the specialties (cardiology, radiology, and vascular surgery) in which endovascular interventions are mainly performed. The EVEREST members work closely together to investigate the applications (PROcedure rehearsal) and implementation of computer-based simulation to improve medical education and patient safety. This team has published extensively on the use of medical simulation in endovascular treatment of vascular disease.
Dr Giora Weisz has recently written an abstract entitled ‘Patient-specific Simulation Enabling Hands-On Rehearsal of Carotid Stenting’ that was accepted by the EuroIntervention Journal. It will be published in a special section, ‘Innovation in Cardiovascular Interventions—Technology Parade 2008.’ In his abstract he states, “Simbionix PROcedure Rehearsal Studio simulates a complete interventional environment and allows rehearsing of a complete endovascular procedure on a virtual model of the patient’s exact anatomy… It creates a simulated interventional environment that provides all the tactile feedback of a real procedure on a real patient, including simulation and display of realtime fluoroscopic images, C-arm operation, and use of catheter laboratory equipment.”13 He also plans to conduct an additional study in which he will examine the correlation between the simulation components of the PROcedure Rehearsal Studio (including anatomy and the procedural components) and the actual angiographic imaging and procedural component. Dr Weisz is Co-Director of Clinical Services at the Center for Interventional Vascular Therapy, New York-Presbyterian Hospital/Columbia University Medical Center and an Assistant Professor of Clinical Medicine at Columbia University College of Physicians and Surgeons. He has extensive experience in performing live carotid stenting cases.
Looking Forward to Ever-increasing Performance
Regarding the future role of medical simulation in procedure rehearsal, Van Herzeele and Aggarwal wrote in an article for US Cardiology regarding the future of virtual reality simulation, “… Physicians can not only ‘warm up’ on a simulator before performing interventions, but virtual reality simulation now allows endovascular therapists to practice complex procedures before performing them in vivo using the PROcedure Rehearsal Studio™ … The endovascular therapist and his or her team can plan the approach, choose the endovascular tools, and address potential complications before a procedure. Furthermore, these types of rehearsals may influence decision-making in the treatment of symptomatic carotid artery lesions.”14
The Simbionx USA Corporation is currently conducting research into expanding the capabilities of the PROcedure Rehearsal Studio to encompass other endovascular procedures. As the technology to create these types of system evolves, the challenge shifts from creating the technology to using it.
Like any tool, it is only as good as the person who uses it, and experience from other fields of professional endeavor have shown that advanced instructional and performance technology is most successful when used as part of a systematic and thoughtful approach to improving performance. As the medical profession continues to define performance goals and metrics for both clinical procedures and the various professional specialties, at the same it will time enhance its ability to use the tools placed at its disposal.