Simulation in Laparoscopic Bariatric Surgery

| June 16, 2010

by James D. Adair, MD; Mark A. Gromski, BA; Ganesh Sankaranarayanan, PhD; Suvranu De, ScD, MA; and Daniel Jones, MD

Drs. Adair, Gromski, and Jones are from the Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts; and Drs. Sankaranarayanan and De are from the Department of Mechanical, Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, New York.

Bariatric Times. 2010;7(6):10–12

In this era of simulation, surgical competency can be first sought within a safe, virtual environment. Surgical trainees can gain valuable practice experience doing various bariatric surgical procedures using computer-based simulators. Computer-based surgical simulators are also valuable to seasoned surgeons learning new or complex procedures. The use of computer-based simulators for surgical training provides a safe, controlled, and realistic learning environment without the need for live animal models.

Weight-Loss Surgery (WLS)
The epidemic of obesity is having a profound impact on health and healthcare systems in the United States. By 2015, there will be greater than two billion individuals who will be classified as obese worldwide (BMI >30).[1] Furthermore, obesity is not only restricted to adults, but is also becoming an increasing burden on the health of adolescents and children and society.[2,3] The three most commonly performed weight loss operations in the United States are the Roux-en-Y gastric bypass (RYGBP), laparoscopic adjustable gastric band (LAGB), and sleeve gastrectomy. With exponential demand by patients for WLS, how do we assure surgeon competency?

Surgical Simulation in Minimally Invasive Surgery (MIS)
Simulation training has taken a much more prominent role in surgical education over the last decade.[4] Emerging technology, increasingly complex procedures, work hour restrictions, and patient safety concerns have forced educators to find alternative ways to train surgical residents. Bariatric surgery, especially the minimally invasive approaches, are technically complex and require advanced laparoscopic skills. While minimally invasive fellowship programs throughout North America have focused on trainees mastering the skills of obesity surgery, simulation offers the potential of allowing trainees to practice and learn in a safe and controlled learning environment.

Fundamentals of Laparoscopic Surgery (FLS) course. With the majority of bariatric operations being performed laparoscopically, WLS surgeons need to demonstrate proficiency in MIS. The Fundamentals of Laparoscopic Surgery (FLS) course teaches principles of laparoscopy and tests surgeons’ video hand skills within a validated box trainer. Most residency-based general surgery training programs in the United States teach FLS as part of their curriculum. Moreover, the American College of Surgeons (ACS) Bariatric Network recommends FLS certification for new surgeons. As of 2009, the American Board of Surgery (ABS) required FLS certification prior to sitting for boards in general surgery, and several hospitals and malpractice carriers currently require FLS certification.[4–6] WLS surgeons who do their own endoscopy and endoscopic operations should also be aware of the Fundamentals of Endoscopic Surgery Program (FES). FES will likely have a similar role in the future of training in endoscopic surgery.

Animal models. As inanimate models and simulators improve, the reliance on live animal models will continue to dwindle. The cost of animals and the ethics involved in utilizing live animals often limit this approach as alternatives become available for training.

Task trainers. Early box trainers allowed for single-task training in the controlled simulation environment, but do not allow for comprehensive, targeted training for specific surgical operations.

Virtual reality. Virtual reality (VR) platforms allow participants to learn components of specific operations while providing procedural feedback.[7,8] VR laparoscopy trainers offer the advantage of providing the availability of unlimited training material, exposure to rare adverse events in the virtual scenario, a customizable training environment, and real-time assessment of performance, without the need for a proctor. Recent studies suggest VR platforms utilized for training purposes may decrease the learning curve on certain procedures.[9] Youngblood et al[10] demonstrated improved surgical performance on porcine models after the completion of a virtual reality laparoscopic simulation training regimen. Naïve subjects trained on a virtual reality simulator performed better on live surgical tasks than those who trained on a traditional box trainer.[10] Interactive three-dimensional models, haptic feedback, and performance tracking are some of the features that can help trainees make the transition from the nonclinical to the clinical setting more successful. In laparoscopic surgery, haptic feedback is an essential component to the operative experience. Earlier VR simulators lacked reliable, functional, haptic feedback, which was a major drawback. Recently, some VR simulators have had the additional function of including haptic feedback.[11] Panait et al[12] described in a recent study how training with haptic feedback allow superior precision, quicker completion of tasks, and fewer technical errors in advanced tasks. Haptic feedback software, however, can be costly. One report estimates that the inclusion of haptic feedback software in VR simulators can add up to $30,000 to the final production price of the simulator.[11] As a whole, cost of VR simulators may be prohibitive, as a large initial investment is often required, as well as significant technical maintenance costs over the lifetime of the simulator. Especially in our current healthcare economic climate, these initial expenses may be discouraging to some institutions. We believe, however, that the proven benefits of this type of simulation outweigh the initial costs.

Most would agree that laparoscopic bariatric procedures have a steep learning curve. Due to the complexity of these surgeries, the goal of simulation training is to traverse the initial portion of the learning curve in the simulation laboratory as opposed to in the operating room with live patients. This may predictably improve clinical outcomes in live surgical cases performed by the trainee.[4]

Laparoscopic gastric bypass VR simulator. At the moment, the laparoscopic gastric bypass procedure remains the most popular and gold standard for WLS. Currently, a VR simulator for training in laparoscopic Roux-en-Y gastric bypass is available from Simbionix as a module of the LapMentor II™ (Simbionix, USA Co, Cleveland, Ohio). This simulator allows for real-life visual and haptic feedback of specific tasks associated with the laparoscopic gastric bypass operation. Internal organs, fluids, and surgical tool instrumentation is modeled in the simulator (Figure 1 and Figure 2). In addition, this simulator has the capacity for the cutting of tissue and anastamosis of tissue using surgical tools such as a linear stapler. Specific steps of the surgery are included in the module, and include creation of gastric pouch, gastrojejunal (Figure 3), and jejunojejunal (Figure 4) anastamoses.

Laparoscopic gastric sleeve. As long-term safety and efficacy data continue to emerge regarding the gastric sleeve procedure, the demand for this procedure may increase heartily. To our knowledge, there are no commercially available VR simulators for the laparoscopic gastric sleeve procedure. It is likely that a VR simulator in this procedure would be very useful, especially if the demand for surgeons capable of performing this surgery increases.

Laparoscopic adjustable gastric band (LAGB) simulator. The LAGB is the second most common surgical intervention performed for weight loss in the United States. Recent reports suggest it is gaining in popularity in the United States over other bariatric procedures.[13] Long-term data continue to emerge that demonstrate the safety and efficacy of the adjustable gastric band surgery.[14]

Research demonstrates that the adjustable gastric band market will grow at double-digit rates, tripling by the year 2015.[13] As the demand for the adjustable gastric band increases, more surgeons will seek the technical skills required to perform this procedure. Currently, surgeons must meet strict standards in order to perform the gastric band procedure. These standards include the demonstration of advanced laparoscopic skill and the completion of a training course, as required by the United States Food and Drug Administration (FDA). In addition, they must have performed several surgeries under the supervision of a surgeon experienced in the procedure.

At present, there is no commercially available simulator for the laparoscopic adjustable gastric band procedure. Recently, we developed the first LAGB VR simulator.[15] It was our goal to optimize both the VR component and the haptic component to produce the most effective simulator for the placement of a gastric band. Our simulator is a VR-based simulator for gastric band placement performed via the pars flaccida approach. This simulator has a custom-built interface and simulation software and provides force feedback to the user. Key steps performed in the virtual surgery are displayed in Figure 5. The realistic virtual environment is capable of demonstrating bleeding, smoke from electrocautery, and injury to adjacent organs, such as perforation (Figure 6). From our initial testing of the LAGB simulator, subjects with varied laparoscopic experience were able to have exposure to this simulation device. Through our trials, we were able to determine excellent face, content, and construct validity.

The face validity scores highlight the positive response of the users to the visual and haptic realism of our simulator. The positive construct validity results demonstrate that the current version of the virtual LAGB simulator can clearly distinguish between expert and novice groups in the performance of necessary tasks of the surgical procedure. The positive content validity results showed that attending surgeons with great clinical laparoscopic experience have a high confidence in the virtual LAGB. The experts agreed that the virtual LAGB simulator would be a useful tool to train residents and surgeons in the LAGB procedure before their first operating room experience.

Limitations of the current design of our novel simulator are similar to the limitations of other VR surgical simulators currently available. First, although our simulator provides excellent force feedback, there is no torque feedback, which would provide for realistic rotational forces. This technology currently is being  developed and is expected to be included in the next generation of the simulator. For haptic feedback, as opposed to many VR surgical simulators, our model uses commercially available devices to produce the force feedback. This most likely will make the commercial price of such a product lower than many available VR simulators.

For minimally invasive surgical training, one study found that training with VR simulators was deemed the second most useful tool for skill acquisition, after basic minimally invasive surgical cases in the operating room.[16] We believe that the new laparoscopic gastric band simulator should be implemented into programs that train surgeons in minimally invasive and bariatric techniques. As the health effects of morbid obesity are increasingly felt by society, and more surgeons desire the requisite skills necessary to perform bariatric surgeries, we believe that there should be more high-quality simulators available specifically for bariatric procedures.

1.    WHO. Obesity and overweight. 2006. Accessed February 10, 2010.
2.    Horgan S, Holterman MJ, Jacobsen GR, et al. Laparoscopic adjustable gastric banding for the treatment of adolescent morbid obesity in the United States: a safe alternative to gastric bypass. J Pediatr Surg. 2005;40:86–90; discussion 91.
3.    Ogden CL, Flegal KM, Carroll MD, Johnson CL. Prevalence and trends in overweight among US children and adolescents, 1999–2000. JAMA. 2002;288:1728–1732.
4.    Tsuda SSD, Doyle J, Jones D. Surgical skills training and simulation. Curr Probl Surg. 2009;46:261–372.
5.    Derevianko AY, Schwaitzberg SD, Tsuda S, et al. Malpractice carrier underwrites fundamentals of laparoscopic surgery training and testing: a benchmark for patient safety. Surg Endosc. 2010;24:616–623.
6.    Tsuda S, Scott D, Doyle J, Jones DB. Surgical skills training and simulation. Curr Probl Surg. 2009;46:271–370.
7.    Hamilton EC, Scott DJ, Fleming JB, et al. Comparison of video trainer and virtual reality training systems on acquisition of laparoscopic skills. Surg Endosc. 2002;16:406–411.
8.    Gurusamy KS, Aggarwal R, Palanivelu L, Davidson BR. Virtual reality training for surgical trainees in laparoscopic surgery. Cochrane Data Syst Rev. 2009:CD006575.
9.    Newmark J, Dandolu V, Milner R, et al. Correlating virtual reality and box trainer tasks in the assessment of laparoscopic surgical skills. Am J Obstet Gynecol. 2007;197:546 e1–4.
10.    Youngblood PL, Srivastava S, Curet M, et al. Comparison of training on two laparoscopic simulators and assessment of skills transfer to surgical performance. J Am Coll Surg. 2005;200:546–551.
11.    Salkini MW, Doarn CR, Kiehl N, et al. The role of haptic feedback in laparoscopic training using the LapMentor II. J Endourol. 2010;24(1):99–102.
12.    Panait L, Akkary E, Bell RL, et al. The role of haptic feedback in laparoscopic simulation training. J Surg Res. 2009;156:312–316.
13.    Paterson HaZ, K. Positive trends in the US gastric band device market despite the economic downturn. Bariatr Times. 2009;6(10):1,7–9.
14.    Carelli AM, Youn HA, Kurian MS, et al. Safety of the laparoscopic adjustable gastric band: seven-year data from a U.S. center of excellence. Surg Endosc. 2010 Feb 5. [Epub ahead of print]
15.    Sankaranarayanan G, Adair J, Halic T, et al. Validation of a novel laparoscopic adjustable gastric band simulator. Surg Endosc. 2010 (in press).
16.    Chan B, Martel G, Poulin EC, et al. Resident training in minimally invasive surgery: a survey of Canadian department and division chairs. Surg Endosc. 2010;24(3):499–503. Epub 2009
Jul 8.

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