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Virtual reality simulation: a paradigm shift in how surgeons and interventionalists are trained

11 June, 2009  

The way physicians are being trained is undergoing radical change driven by concerns about patient safety and how groups such as surgeons, interventional cardiologists and interventional radiologists can be better prepared

Anthony G Gallagher PhD, Professor of Human Factors, National Surgical Training Centre, Royal College of Surgeons in Ireland

Medical specialties such as surgery, interventional cardiology and interventional radiology are currently undergoing a paradigm shift in how they conduct training. A paradigm shift is a change from one way of thinking or doing something to another. It is a revolution, a transformation, a sort of metamorphosis and it doesn’t just happen, but rather agents of change drive it.[1]

Although the minimally invasive surgical (MIS) revolution in surgery may have instigated the process of change, other events outside surgery acted as catalysts and accelerated the process of thinking about a better way to prepare physicians for the operating room. It became clear with the introduction of MIS that this new way of performing surgery was associated with higher complication rates,[2] particularly early in the surgeon’s laparoscopic experience.[3]

This sensitised the general public to the issue of medical errors. Compounding this awareness were two seminal events. In the UK, three consultant paediatric cardiac surgeons were dismissed from their positions at the Bristol Royal Infirmary for complications that were “unacceptably high”.[4] In the USA, the Institute of Medicine claimed that up to 98,000 patients per year died due to medical error.[5] Both of these cases negatively impacted on public confidence in medicine.

During most of the 20th century physicians and their training were held in very high esteem by the general public. However, with the introduction of MIS it became clear to the general public that patients themselves provided the primary in-vivo training resource for interventional medical disciplines such as surgery.

The way in which interventional disciplines such as surgery trained had gone almost unchanged from the programme developed by Halsted at Johns Hopkins at the end of the 19th and beginning of the 20th century. With the introduction of MIS there was widespread acceptance from the medical community that this training paradigm was no longer optimal for the efficient and effective acquisition of safe procedural skills. Furthermore, there was a growing consensus amongst the medical community that acquiring skills on patients, particularly at the start of the learning curve, was no longer acceptable.

Compounding the problems of training doctors were changes in Europe and the USA to reduce working hours of doctors. In the USA the recommendation of the Bell Commission was that working time for doctors in training should be reduced to 80 hours per week.[6] The European Working Time Regulations that now apply to the vast majority of workers stipulated that the time people spend at work should not exceed 48 hours (including overtime) when averaged over a 17-week period.[7]

Virtual reality: a better way to train
Colonel Richard Martin Satava was a general surgeon working for the US military in the early 1990s. He identified virtual reality (VR) simulation as a potential solution for the difficulties. His surgical colleagues were encountering in-training surgeons to perform MIS. VR was already stateof-
the-art for training in many other high-risk, high-skill professions. Satava first introduced surgery to VR simulation in 1992 (Figure 1), but medical community but also due to the lack of well-controlled clinical trials.[8]

In 2002 a multidisciplinary team at Yale University conducted the first prospective, randomised, double-blind clinical trial to test whether training on a VR simulator translated into improved intraoperative performance. The trial compared the performance of a group of residents who received standard surgical residency training with a case-matched group who received proficiency-based training on the Minimally Invasive Surgical Trainer, Virtual Reality (MIST VR).

The VR-trained residents trained for as many trials as necessary to reach the quantitatively defined criteria (ie, level of proficiency). Both groups were then objectively assessed on their ability to dissect the gallbladder from the liver bed during a laparoscopic cholecystectomy.[9]

The results of this study showed that the VR-trained residents performed the procedure 30% faster and made six times fewer objectively assessed intraoperative errors when compared with the standard-trained residents. These results have been independently replicated in Sweden using a similar scientific study design.[10]


Why does simulation training work?
Computer-based simulation has several advantages when compared with conventional training methods. One of the major advantages of simulation is that the same experience or sequence of events can be replicated repeatedly. This repetition allows the trainee to learn from mistakes in a safe environment.

Another benefit that is probably equally if not more important is the objective feedback a trainee can receive from a computer-based simulator. Since everything a trainee does on a computer-based simulator is essentially data, all actions can be tracked by the computer. In addition to crude measures such as performance time, detailed data such as instrument path length, speed of instrument movement and exact location in space of any instrument at any point in time is recorded.

While these data alone are meaningless, it can be used by subject matter experts to create a set of robust and objective performance metrics. While the main function of metrics is to provide the trainee with objective and proximate feedback on their performance, they also allow the trainer to objectively assess the progress of the trainee throughout the training process.[11]

The most valuable metrics that a simulation can provide is identification of errors. The whole point of training is to improve performance, make performance consistent and reduce errors. One of the major benefits of simulation is that trainees are allowed to make mistakes in a consequencefree environment, before they ever perform that procedure on a patient, but if a simulator allows a trainee to perform an unsafe manoeuvre without identifying it as an error, dangerous behaviours can be trained, possibly becoming difficult to untrain later.

A good simulator with well-designed metrics is a training system where trainees can learn both what TO do and what NOT to do before operating on patients. Any simulator without robust metrics is just an expensive video-game.


Proficiency-based progression VR simulator training
The traditional way that simulation has been applied to training is through a prescriptive approach. Typically the trainee is required to train for a prespecified number of trials or number of hours. However, all that this approach achieves is considerable variability in posttraining skills.[11]

Individuals start from different baseline skill levels, they learn at different rates and some are more gifted than others. Simulation allows for levelling of the playing field and sets a skill “benchmark” that individuals can reach at their own pace.

Furthermore, trainees should not be allowed to progress to the next phase of training until they demonstrate that they are performing proficiently and consistently. The Yale and Swedish VR to OR studies have shown the power of this approach.[9,10]

Proficiency-based interdisciplinary simulation training
Proficiency-based training as a new approach to the acquisition of procedural-based medical skills took a major step forward in April 2004. As part of the roll-out of a new device for carotid artery stenting (CAS), the Food and Drug Administration (FDA) mandated, as part of the device approval package, metric-based training to proficiency on a VR simulator as the required training approach for physicians who will be using the new device.[12]

The company manufacturing the CAS system informed the FDA that they would educate and train physicians in catheter and wire handling skills with a high-fidelity VR simulator using a curriculum based on achieving a level of proficiency.

This approach allows for training of physicians who enter training with variable knowledge, skill and experience to leave with objectively assessed proficient knowledge and skills. This is particularly important for a procedure such as CAS as it crosses multiple clinical specialties with each bringing a different skill set to the training table.

For example, a vascular surgeon has a thorough cognitive understanding of vascular anatomy and management of carotid disease, but may lack some of the psychomotor technical skills of wire and catheter manipulation. Conversely, an  interventional cardiologist may have all of the technical skill, but may not be as familiar with the anatomical and clinical management issues.

A sound training strategy must ensure that all of these specialists are able to meet an objectively assessable minimum level of proficiency in all facets of the procedure. This development helps to consolidate the paradigm shift in procedural- based medicine training and will result in a reduction in “turf wars” concerning future credentialling for new procedures. As long as a physician is able to demonstrate that he or she possesses the requisite knowledge and skills to perform a procedure, specialty affiliation will become less important. Indeed, this was the approach advocated by a number of the professional medical organisations intimately involved in training physicians for CAS.[13]

Now and the future
Surgeons, interventional cardiologists, radiologists and endovascular surgeons now have the opportunity to learn to perform procedures such as CAS on a full procedural VR simulator (eg, VIST).[14] This complete simulation package probably represents one of the most advanced VR
packages for medical simulation currently available in the world today.

The implication of having this quality of simulation and objective metrics readily available is that only physicians who clearly demonstrate proficiency on the simulator will be approved to carry out the procedure on patients. VIST is also the first VR simulator that will really allow a physician to rehearse a very difficult procedure before doing it in vivo (ie, mission rehearsal).[15]

The potential of VR for patient safety, improved training, and development and market roll-out of new procedures is very exciting. However, truly demonstrating the value of this technology as a training device will require multiple,
well-controlled trials.[14]

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KC, Roubin GS, Weiner BH, White CW. SCAI/SVMB/SVS Clinical Competence Statement on Carotid Stenting:
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JAMA 2007;297:265-6. acceptance of the VR training approach has been slow partly because of scepticism within the