What is the role of surgical simulators?

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In gynecologic surgery, surgeons are expected to acquire high levels of experience before performing surgeries, but they need to perform surgeries in order to gain experience. One proposed solution to this paradox is using surgical simulators. Here, four physicians discuss the merits of incorporating simulators into surgical training.

Ms. Wetzel: How do surgical simulators work and can they take the place of actual surgical procedures in training and certification? 

Dr. Einarsson: I think simulators have potential to be very useful in training. Low-fidelity simulators-box trainers-are perfectly adequate but the science of simulation is somewhat lacking. Studies show that learner skills do improve after practice with a simulator, compared with results prior to use of the technology.¹ To me, that’s not very surprising. I would be much more interested in knowing whether learners retain knowledge and skills gained from simulators over the long term and if that translates into superior clinical outcomes. Those are important questions and I understand that in medicine, we use intermediate outcomes for teachability sake, but I think we need better science in simulation.

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Dr. Munro: I agree that the science needs to be better. Many people think that surgical simulation means going into a virtual environment and simulating an entire operation.  However, we are nowhere close to having realistic immersive simulation in which a learner can actually work on a virtual patient with a spectrum of virtual anatomical and pathological circumstances. Instead much of what we have is simple technology that simulates parts of the task or skill that we believe are useful, circumstances that may reflect something about the physical abilities of the individual. And this sort of simulation doesn’t take into account surgical judgment. Truly meaningful outcomes with simulation would include the impact of simulation-based training on safety, efficacy, quality of life, cost reduction, or some combination of those. But assessing these outcomes would be quite expensive. So important questions facing us right now include: Who are the stakeholders for surgical simulation and where is the funding going to come from to study real-world outcomes?

Dr. Moawad: I have a different perspective on simulation. Simulations are not going to create the surgeon but they can help enhance hand/eye coordination and ambidextrous surgery, among other things, and facilitate the learning curve and help with team-building and managing complications. I believe that the value of simulation lies in shortening the learning curve for the learner and providing a safe environment in which it’s permissible to make mistakes, explore what went wrong, and ask questions.

Dr. Munro: Where possible, we also have to try to determine outcomes for simulation training that are meaningful and that will guide us in designing the technology and the way in which it’s used. Simulation is a part of an overall change in the training paradigm that spans a range of components of care such as determining who to operate on and how the surgeon should be prepared to execute the technical aspects of performing the procedures. Our disease state management is basically that of uterine and adnexal disease so our training has to be in that context.

Ms. Wetzel: What kind of simulators are currently available and what do practitioners need to know about using them? Which simulators do you prefer and why? 

Dr. Einarsson: A lot of different simulators are available. The simplest are low-fidelity trainers that are basically a box with a small camera and a light, into which instruments can be placed to practice. The box trainer most widely used right now is the FLS Trainer.² And then you have virtual reality (VR) trainers that try to simulate more procedures than the actual intraoperative environment.³ I really like the box trainers because they’re relatively inexpensive and can be used in different places and under varying conditions to gain dexterity and experience with techniques such as intracorporeal and extracorporeal mopping. Developing VR trainers that are meaningful is money- and resource-intensive. We had a VR trainer at our simulation center and every time I used the ectopic pregnancy module, the patient bled to death. I’ve never had a patient bleed to death in real life from an ectopic pregnancy. So, I think that there’s still some developmental work that needs to be done on VR surgical trainers.

Dr. Munro: I think the first consideration is framing what is it that you’re simulating. In gynecologic surgery, we have abdominal access, both laparotomic and laparoscopic approaches, the latter done with and without microprocessor assistance. Vaginal approaches include hysteroscopic technique and surgery on the cervix and, hysterectomy when removal of the uterus is necessary. Should all of those aspects be simulated for residency training? The American Board of Obstetrics and Gynecology (ABOG) has acknowledged the importance of simulation-based training in laparoscopy by requiring that residents in obstetrics and gynecology graduating after May 31, 2020 pass the Fundamentals of Laparoscopic Surgery (FLS) examinations developed jointly by the Society of American Gastrointestinal and Endoscopic Surgeons and the American College of Surgeons. Many residency programs, however, have trouble affording a surgical simulator unless it’s inexpensive. But there is really no evidence that VR laparoscopy trainers do a better job at what is being measured than the low-fidelity systems.

On the hysteroscopy side, VR is actually more realistic and more attainable. There are a number of quite decent VR systems for hysteroscopy and one of the reasons that it’s easier to engineer those in that the environment is like being in a small room. In the laparoscopy environment, in contrast, you have to simulate interaction with the bowel and the level of complexity is exponentially greater. Simulation is hardly being done for vaginal hysterectomy and it remains a very low morbidity procedure with no abdominal incisions, but one that requires certain skills. Simulation should be considered for the multiple approaches to and processes associated with vaginal hysteroscopy to see what the likely benefit of the procedure might be. We’ve examined two low-fidelity surgical simulation systems-one for hysteroscopy and one for laparoscopy. Both can be used reasonably well by novices, mid-level trainees, people without extra training in gynecologic surgery, and people who have done a 2-year fellowship in it. Low-fidelity simulation is quite feasible, and quite usable.

Dr. Moawad: If we’re going to devise surgical simulation, first we need to determine its goal. If we’re looking at training for depth perception, hand-to-hand coordination and ambidexterity, which are the basic principles of surgery, I believe that low-fidelity simulators are always the best. What they lack is the feel of real tissue and plane dissection. The latter can be learned by watching realistic videos. I think virtual simulation has a role if we’re looking at the efficiency of movements and how to maximize it. Calculations can be done about the number of unnecessary moves to establish how efficient a surgeon is.  

But virtual simulations are being marketed as depicting procedures so super-realistic that training on them will give someone the ability to do the real surgery in real life. But they’re very far away from reality in many metrics. I think each simulator adds something but we need a combination of them. For example, using a bell pepper for hysteroscopy, chicken for laparoscopy, and beef tongue for suturing or tissue extraction are really very valuable in terms of immersing trainees in actively performing surgical steps on real tissue.

Dr. Ascher-Walsh: A few years ago, we started a research project with our insurance carrier with the eventual goal of trying to find a simulator for use for credentialing or for continuation of privileges. We tried a lot of simulators and decided on the Surgical Science simulator because we thought it was as close to real life, at that time, as we could find. But, there’s really nothing that mimics real surgery, although some of the newer simulators have tactile feedback. My perception is that simulation is good for learning the steps of a procedure, and it may help people who didn’t grow up playing video games to develop the hand/eye coordination necessary for laparoscopy.   However, we’re far from using it learn the intricacies of surgery and create talented surgeons. Things like tissue planes, which experienced surgeons see innately don’t really exist within simulation at this point. 

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Dr. Munro: I think we may potentially be able to use simulation to help identify who should or shouldn’t be admitted to surgical training programs. Ability to use a surgical simulator could be a criterion for entry, either into residency or into a fellowship. For years now, in North America, dentists have had to demonstrate manual dexterity in order to get into dental school. I don’t know what evidence the dentists had when that criterion was introduced, but it doesn’t matter how smart you are if you can’t do a good job with manual skills. Simulation-based testing also could function as a formative examination for surgical skill, a skill-based component of the CREOG in-training exam (ITE). The ITE is administered to residents annually to evaluate their cognitive knowledge but we have no equivalent for surgery. As was previously mentioned, ABOG will now be requiring that residents in obstetrics and gynecology pass the FLS examinations that were designed for general surgeons. But the only component of gynecologic surgery that’s tested under FLS is laparoscopy and, if we’re restricted to that, then we’re creating one-arm surgeons. There is no testing for hysteroscopy, vaginal surgery, or laparotomy. Maintenance of certification also is another possibility for simulation-based testing. And simulation could be used to train gynecologists on use of new equipment and new techniques that are introduced, much as is done by the US military or in civil aviation. For example when new fighter aircraft are built, training and credentialing systems also are created for that machinery and are used as critical and essential hurdles to the overall process of certification. In my opinion surgical simulation based training and testing should ultimately be used in a similar fashion for surgeons of any discipline. 

Dr. Einarsson: I think the simulators that offer the biggest bang for the buck, so to speak, are the low-fidelity simulators, which could be used to help residents pass the FLS test that will soon be a requirement for graduation. I think both graduating residents and physicians in practice should become familiar with the low-fidelity simulators. They should be made available in every ob/gyn residency program rather than virtual reality trainers, which are more expensive.

Dr. Munro: A number of inexpensive and portable low-fidelity simulators are available that incorporate iPhones or iPads as the camera and light source, in a fashion that allows for and supports manual skills training.  They aren’t exactly the FLS trainer that we’ve talked about, but they can be accessible to anyone who wants to learn or hone manual skills. 

Dr. Einarsson: When I was a resident, I made my own simulator out of a cardboard box, a video camera - there were no iPhones then - and a flashlight.  And it worked quite well. So a simulator doesn’t have to be very fancy to be useful.

Dr. Ascher-Walsh: I completely agree. I really don’t feel like we’ve come very far with simulation in the last 15 years or 20 years, because the devices we have are still just teaching the basic tools. The fancy simulators can walk you through the steps of a procedure, but you’re really still just using the basic tools of surgery. Simulators don’t create great surgeons but they can give you the simple tools that you need to then become a great surgeon.

Dr. Moawad: I feel that simulation could play a role in recertification, but unfortunately, recertification is now based on volume rather than multiple metrics that could lead to better outcome. The other thing we need to work on is the whole system. Recertification should enable us to triage people who would benefit the most from simulation or from a specific aspect of simulation to better their skills and make them have better surgical outcomes.

Ms. Wetzel: What other options for simulation are on the horizon and do you see simulators being integrated more completely into your own clinical practices?

Dr. Einarsson: I think that the most exciting thing that’s on the horizon is really the launch of the Essentials in Minimally Invasive Gynecology (EMIG) test, which has been in development for some time now by AAGL, ABOG, and CREOG. EMIG is a three-part program designed to aid and evaluate the acquisition of manual and cognitive skills in hysteroscopic and laparoscopic surgery. It includes a curriculum, written examination, and manual skills test. I hope EMIG will be integrated into clinical practice in the near future and hopefully represent a minimum standard of proficiency in hysteroscopy and laparoscopy that providers should have to meet to have the privilege of operating on patients.

Dr. Munro: The laparoscopic component of EMIG is performed the FLS box trainer, with exercise and instructions that have been adapted in a way that we believe is appropriate for gynecologic trainees - from novices to mid-level trainees to board-certified ob/gyns and also those who are training for FMIGS and other surgical fellowships. We’ve also created a relatively simple box trainer for hysteroscopy but we’re still challenged by the expenses of having the scope, light source, and camera, and there is currently no way to adapt the trainer for the iPhone or similar easily accessible monitors. We don’t yet have a simulator for laparotomic or vaginal surgery. Hysteroscopy is strikingly missing from a lot of the discussions about simulation on a national level – an omission which is concerning. It is lesions in the endometrial cavity such as polyps and myomas that most often are responsible for infertility and abnormal uterine bleeding, and the hysteroscopic surgeon is the one often best equipped to deal with them in a minimally invasive fashion. And of course, the hysteroscopic surgeon and the laparoscopic surgeon should be one and the same, making decisions on the technique based upon optimal training and skill rather than what they are comfortable with based on limited training. As Dr. Einarsson has said, gynecologic surgeons need to be adept at hysteroscopic, laparoscopic, and vaginal procedures to call themselves gynecologic surgeons. So, the next step in introducing simulation to our trainees is to make them applicable to the two endoscopic approaches we use.

Dr. Ascher-Walsh: For me the only way I see simulation getting integrated into clinical practice is for surgeons who don’t operate very much. For high-volume surgeons, simulation in its current state, which is really not very lifelike, doesn’t help us in our clinical practice. But for surgeons who do a dozen cases a year, simulation may be helpful in credentialing or assessing whether to continue privileges. For those low-volume surgeons, I would see simulation as part of their clinical practice in maintenance of skills.  

Dr. Moawad: Where I see simulation, not only for the novice surgeon but also for the experienced surgeon, is integration of case-specific simulation. For example, anatomy could be reconstructed in three dimensions (3D) based on imaging and then the trainer, the mentor and the learner could use it to review that specific case. We might use it to simulate models for incision of fibroids or to test scenarios for addressing a complex case in a different way. In the future, 3D printing and reconstruction combined with case-specific simulation may prove very helpful before the case itself.

Dr. Munro: I agree. There are certain circumstances in which a case may be so challenging that 3D reconstruction could help identify who you need in the room, what resources, and even where to dissect. For example, for complex neurosurgery, surgeons are increasingly using 3D reconstruction using of MRI volumes and 3D printers have been used to assess vascularity and other factors, allowing the surgeons to understand how to dissect in a very difficult field.  As Dr. Ascher-Walsh said, we aren’t even remotely close to that but I think one of the potential advantages of a true virtual reality immersive experience, is the opportunity to actually practice the operation and be a little bit closer to what happens, like commercial or fighter aircraft simulation, where it really is a realistic immersive experience. In fact, the simulation systems for fighter aircraft are so sophisticated, that training planes are no longer made – the pilot goes straight from the simulator to solo flying in aircraft worth hundreds of millions of dollars.

Dr. Einarsson: Until we are there, I think using low-fidelity simulators and watching videos can be very, very helpful for surgeons. I want to put a small plug in for the SurgeryU platform that the AAGL has developed. It has a lot of very high-quality surgical videos that AAGL members can access. There are other sources of surgical videos available as well. I think that those two components are most easily accessible currently and then hopefully this will evolve into a more sophisticated offering in the near future or maybe the far future.

Dr. Munro: To go back to the EMIG program, I’d like to emphasize that it isn’t just manual skills. There is an entire cognitive program that comprises 80 training videos which encompass the spectrum of hysteroscopic and laparoscopic surgery procedures and patient preparation. There is an accompanying didactive component is designed to measure judgment that will be mounted on the AAGL’s SurgeryU website. The cognitive exam that has been validated and, in an ongoing fashion is modified and revalidated using high quality, psychometrician supported methodology. This examination, meant to evaluate judgement, is paired with the manual skills exam to provide an overall assessment of progress. So the EMIG system is more comprehensive than just an assessment of manual skills.

Ms. Wetzel: In conclusion, please sum up for our readers where you see surgical simulation today and what’s on the horizon in terms of simulation science.

Dr. Einarsson: Simulation is still somewhat in its infancy. The low-fidelity simulators are the most easily usable and are probably going to be more integrated with the FLS test and then hopefully the EMIG test. I think we need better science and also probably better technology in the area of surgical simulation. 

Dr. Moawad: The most important point about surgical simulation, for me, is that use of simulation in isolation from any teaching method will furnish the learner with some skills but the best time and place to learn most of the skills will still be the traditional way, in the operating room (OR). In addition, surgical judgment is really hard to learn and I think simulation could provide a safe environment in which to learn how things can go wrong and how to readdress them. Simulation could help gynecologic surgeons build  confidence to enable you to apply those kind of competencies in a real OR.

Dr. Ascher-Walsh: Where we’ve had some early success with simulation is in establishing credentialing. We’ve done some projects with a very large health system looking at a few hundred attendings and correlating their surgical skills on the simulator with their case experience. We were able to find some correlation between the two and we’re now comparing it to actual surgical videos with the hope of being able to use it as a credentialing tool. I think, as everybody else was saying, we’re sort of far away in using simulation as an advanced surgical training tool. I agree that the low-fidelity simulators are the best tools for the surgeon early in training. For low-volume surgeons, it also may be a way to maintain their skills. I hope that in the next decade, as the science improves, we’ll be able to have more realistic simulation, but we’re not there now.

Dr. Munro: In gynecology, we are awakening to the notion that we have an increasingly complex challenge in the disease states that we are entrusted to manage. That challenge has to be taken into consideration when developing a structured approach to training and evaluation of residents and fellows at a spectrum of benchmark times in the training process. It’s both a moral and legal imperative. We need to improve how we train gynecologic surgeons, and simulation is only  part of the answer. Right now, simulation is only a nascent adjunct to training, and, at least in present forms, the low-fidelity simulators are at least equivalent to expensive virtual reality systems. The future requires science, investment, creativity, and an understanding that ultimately the patient expects that her physician and surgeon have a consistent and predictable level of skills. The patient’s level of trust should be similar to that vested in the pilot of the commercial aircraft of her selected airline. Finally, simulation isn’t just for laparoscopy. Simulation and surgical training involves hysteroscopic, laparoscopic, laparotomic and vaginal approaches, because all are essential skills for the contemporary gynecological surgeon.

Disclosures:

The participants report no potential conflicts of interest with regard to this article.

References:

• Alaker M, Wynn GR, Arulampalam T. Virtual reality training in laparoscopic surgery: A systematic review & meta-analysis. Int J Surg. 2016 May;29:85-94.

• https://fls-products.com/fls/search/?searchTerm=fls-trainer-box-with-tv-camera-with-tasks

• https://simbionix.com/simulators/lap-mentor/lap-mentor-vr-or/

• Munro MG, Brown AN, Saadat S, et al. Essentials in minimally invasive gynecology manual skills pilot validation trial. J Minim Invasive Gynecol. 2019 Apr 26. pii: S1553-4650(19)30205-5.