- Email: [email protected]
Simulation Training in Surgery
Simulation Training in Surgery Michael Ujiki, MD, FACS, and Jin-cheng Zhao, MD, MS Surgical training consists of developing cognitive, clinical, and technical skills. Current surgical training in the USA is based on the German-style residency training system introduced by Sir William Halsted at Johns Hopkins Hospital in 1889, with an emphasis on graded responsibility, in which the surgical technical skills in the resident programs were traditionally acquired through mentoring.1 However, recent advances in minimally invasive surgical technology, educational and motor skill learning theory, and mounting pressures in the clinical environment have raised questions about the reliance on this approach to teaching technical skills in the young generation of surgeons. Therefore, replication of surgical situations through biological models, such as animals and human cadavers, and more recently, the development of nonbiological simulators housed in training laboratories or centers, have been developed.2
Development of Simulation Training in Surgery Advanced Development of Technology in Surgery Revolutionary technological developments in the area of surgery have provided unprecedented opportunities to create an impact on surgical treatment. The growth and more extensive application of minimally invasive surgical techniques are expected to continue to rise. Therefore, the required performance of relatively complicated technical and intellectual tasks in such an environment present the contemporary surgeons with unexpected and serious challenges during the operations with little or no room for error.3 This has raised concerns regarding patient safety and highlights the need to supplement training outside of the operating room. Similar to airline pilot simulation, practicing technical skills in a controlled, risk-free environment may allow surgical trainees to develop and master surgical maneuvers safely. It also provides a means for objective, standardized assessment of skills performed by the learners.
Dis Mon 2011;57:789-801 0011-5029/2011 $36.00 ⫹ 0 doi:10.1016/j.disamonth.2011.08.018 DM, December 2011
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Cognitive Theory In surgical training, the learning curve is the process and time during which the learner acquires the motor skills required to adequately perform surgical procedures. Fitts and Posner’s theory of skill acquisition is currently widely accepted in both the motor skills and the surgical literature.4,5 Their theory is composed of 3 stages. In the cognitive stage, the learner intellectualizes the task; performance is erratic, and the procedure is carried out in distinct steps. After repetitive exercises and feedback, the learner reaches the integrative stage, in which knowledge is translated into appropriate motor behavior. Although still thinking about each action, the learner is able to execute the task more fluidly, and with fewer interruptions. In the autonomous stage, action becomes habit, gradually resulting in smooth performance. The learner no longer needs to think about how to execute a particular task and can concentrate on other aspects of the procedure. This model has obvious implications for surgical training. Early stages of learning technical skills take place outside of the operating room; practice is the rule until automaticity in basic skills is achieved. Finally, mastery of basic skills allows trainees to focus on more complex issues, both technical and nontechnical, in the operating room. In general, expertise is established through repetitive purposeful practice, and not volume alone.6 Volume does not account for the skill level among practitioners, because variations in performance have been shown among surgeons with equally high volumes. Purposeful practice is a critical process in the development of mastery or expertise of a technical skill. In the current model of surgical training, the operations are complex, and it is difficult for learners to focus on one small component of the skill and procedure. Theoretically, opportunities for purposeful practice can only be achieved in a simulated environment. In the surgical simulation laboratory, the learners focus on a defined task, typically identified by a teacher, to improve particular aspects of performance; the practice can be repeated along with coaching and immediate feedback on performance.
Challenges in Clinical and Operating Room Environments Clinical situations in surgery have changed dramatically, with increasingly complex procedures, work hour restrictions, and patient safety concerns.7 These situations result in diminished teaching time and have forced surgical educators to find alternative ways to train residents. This 790
DM, December 2011
is especially true in minimally invasive surgeries, which are technically complex and require advanced laparoscopic skills. Patients in teaching hospitals are generally much sicker and have more complex problems than in the past. The increasing complexity of cases and a greater emphasis on mitigating medical error limit the faculty’s latitude in assisting residents with technical procedures. Sheer volume of exposure is the hallmark of current surgical training.8 However, as opportunities for learning through work with “real” patients have diminished, interest in laboratories with specifically designed formal curricula has gradually incorporated into an important model of surgical education, in which basic surgical skills, specific techniques, and some procedures are learned and practiced on models and simulators, with the aim of better preparing trainees for the operating room experience.7,8
Current Status of Simulation Training in Surgery The field of surgical simulation is rapidly evolving and consists of development of simulation models, curriculum, and assessment. A wide variety of models are available for teaching surgical technical skills. These range from high-fidelity models, such as training on animal models, to virtual reality simulators, and lower fidelity video trainer boxes. A trainer box is rather simple and includes a box with slits on the top for laparoscopic trocar insertion. Real laparoscopic instruments are inserted through the trocar into the box. A camera inside the box provides video output to a monitor, on which trainees can watch their own movements. This model can simulate a variety of skills and techniques, including basic laparoscopic instrument handling, transferring objects, cutting, suturing, knot-tying, and clip-applying, through which brain, eye, and hand coordination can be built. The limitation of the trainer box is that it simulates only certain surgical skills rather than an entire operation. The Fundamentals of Laparoscopic Surgery (FLS) Program was first established at the National Meeting of the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) in 2004. FLS is a comprehensive, CD-ROM-based educational curriculum for laparoscopic surgery designed to teach the physiology, fundamental knowledge, and technical skills required in laparoscopic surgery. FLS has 3 parts: a CD-ROM study guide, a laparoscopic trainer box, and an assessment component.9 The FLS trainer box is now used for required training for all graduating surgical residents and was chosen because it is inexpensive, portable, and reproducible (Fig 1). Moreover, the optical system and instrumentation used are similar to those used in the operating room. DM, December 2011
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FIG 1. FLS box setup. A digital video camera is installed inside the trainer box so that no scope is needed. The camera can be connected to laparoscopic tower monitor, TV monitor or laptop for viewing. Two laparoscopic ports are inserted. (Color version of figure is available online.)
The FLS program consists of 5 exercises to develop manual laparoscopic skills: peg transfer (Fig 2), pattern cutting (Fig 3), loop ligation (Fig 4), extracorporeal (Fig 5A), and intracorporeal (Fig 5B) knot-tying. An instructional CD-ROM video demonstrates each exercise in a “‘watch and do’” manner. These exercises are non-procedure-specific and are designed to improve the technical facility of a basic laparoscopic skills set. Once a trainee feels that he or she has mastered these 5 skills, an examination to test competency is available at either an approved testing center, the annual SAGES meeting, or the trainee’s own institution if the hospital has purchased the educational package. SAGES has worked hard to validate FLS training and assessment. A high inter-rater reliability and test–retest reliability have been demonstrated with correlation coefficients 792
DM, December 2011
FIG 2. FLS task 1, peg transfer. This requires trainee to lift the six objects with a Maryland dissector or grasper in the non-dominant hand, transfer midair to another Maryland dissector or grasper in the dominant hand. Then place each object on the other side of the board. Once the transfer is completed, the process is reversed. (Color version of figure is available online.)
FIG 3. FLS task 2, precision pattern cutting. This exercise requires trainee to cut out a circle from a square piece of gauze suspended between clips. (Color version of figure is available online.)
of 0.99 and 0.89, respectively.9 Further validity has been demonstrated with residents at different levels of training showing progressive improvement in their scores.10 More significantly, surgeons who are highly rated on their technical skills in the operating room have higher FLS scores than those who perform poorly.11 DM, December 2011
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FIG 4. FLS task 3, placement and securing of ligating loop. The trainee is required to place a pre-tied ligating loop or endoloop around a tubular foam appendage on the provided mark. (Color version of figure is available online.)
The careful creation and implementation of the FLS program make it the first available education training curriculum in laparoscopic surgery that not only teaches technical skills but also provides educational content, all in a highly validated simulation package. The use of a box-trainer allows this model to be easily distributed and administered, and the cost is acceptable. To make use of the box-trainer even easier, a company named Simulab Corporation from Seattle, Washington (http:// www.simulab.com) has created SimuVision, a boom-mounted digital camera that has the look and feel of a real laparoscope but connects to a laptop or personal computer rather than a video monitor. This allows for the creation of a portable simulated environment that uses an optical system and real surgical instruments the trainee can even take home. Alternatively, computer-based virtual-reality simulators with combined metric systems, such as MIST-VR (Minimally Invasive Surgery Trainer– Virtual Reality), is used to provide feedback to novice learners during practice. The acceptable cost and quantification of performance of the early version provides an alternative tool for surgical training in addition to the trainer box (Fig 6).12 The fidelity of virtual reality simulators range widely, from MIST-VR to systems that teach component procedural skills and replicate entire operations. Such systems allow for practice at variable levels of difficulty, can simulate complications, and automatically provide objective measures of assessment, allowing for both formative and summative trainee 794
DM, December 2011
FIG 5. (A) FLS task 4, extracorporeal suturing. This task requires trainee to place a simple stitch through two marks in a longitudinally slit Penrose drain. Then the knot is tied extracorporeally using a knot pusher to slide the knot down. The knot must be tied tightly enough to close the slit in the drain. (B) FLS task 5, intracorporeal suturing. This task requires trainee to place a simple stitch through two marks in a longitudinally slit Penrose drain using needle holder or Endo-stitch and tie the knot intracorporeally. The knot must be tied tightly enough to close the slit in the drain. (Color version of figure is available online.)
assessment. The trainee’s performance can be monitored and recorded in an exportable database; more importantly, student curricula can be custom designed, and a Web-enabled platform allows for remote administration.13,14 Some more complex virtual-reality computer-based simulators have haptic features that allow for man–machine interface and a realistic sense of touch. Some are even more sophisticated and provide a DM, December 2011
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FIG 6. MIST-VR, a computer-based virtual-reality simulator. (Color version of figure is available online.)
graded response that allows for differentiation from structure to structure, degree of pushing against a structure, and the sensation of pulling, stretching, spreading, and the like.3 However, the advanced computer-based simulators are not popular because of cost ($36,000-$80,000, plus $8000-$15,000 annual service fee) and because of haptics that are still far from reality. Additionally, some studies show that virtual reality simulators are no better than a video-cart system in training novices in laparoscopic skills.15 Virtual reality simulators cannot yet replace animal models and human cadavers when it comes to surgical training. The advantages of animal models include a more realistic environment, and opportunities to mimic intraoperative complications, such as hemorrhage. However, there are many disadvantages to the use of animals, including cost, anatomical differences with humans, and their ethical use.16 Human cadavers are used, but have several disadvantages as well, including cost, limited availability, and an inability to simulate certain intraoperative complications, such as bleeding.13 Sutherland et al performed a systematic review of 30 studies on surgical simulation in the literature. Simulation training was divided into 4 types: 796
DM, December 2011
computer, video, model, and cadaver. These 4 methods of simulation training were compared to each other as well as to standard surgical training in the article.2 The following is a summary of these comparisons. Computer Simulation vs No Training. Learners who trained on computer simulators performed better than those who received no training at all. Computer Simulation vs Standard Training. When computer-simulator-trained students were compared with students who received standard training (eg, surgical drills), the superiority of computer simulation was less pronounced than for “no training” comparisons. The computer simulation vs “standard” training comparisons varied, potentially confounded by the different components of “standard” training, as well as by the different intensities of time allowed on the simulator in the computer simulation groups. Computer Simulation vs Video Simulation. Computer simulation showed mixed results, superior in some studies, but not others, and was inferior to video simulation in one study. This may have depended on types of tasks, with computer simulation producing better results for tasks, such as incisions, but not for knot-tying times. However, there were too few studies to determine this. Computer Simulation vs Physical Trainer or Model. One study showed computer simulation training to be superior to training on a physical trainer. Two or More Types of Computer Simulation: MIST-VR. One randomized controlled trial showed that more demanding training may lead to better performance of surgical tasks on MIST-VR. Another randomized controlled trial failed to show clear differences between massed and distributed practice on MIST-VR. Video Simulation vs No Training. Video simulation groups did not show consistently better results than groups who did not receive training. Video Simulation vs Other Forms of Training. No differences were seen between video box training and other forms of training, such as bench models or standard training. Physical or Model Simulation vs Other Forms of Training, Including No Training. These comparisons showed mixed results; model training may be better than no training and standard training, such as instruction from mentors or manuals. Cadaver Training vs Standard Training. The cadaver-trained group received better scores than the standard training group, who learned independently from the manuals, for the global assessment of operative performance on cadavers (66.5 vs 51.5) and the checklist score (69.5 vs DM, December 2011
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60.5), although it was not stated whether these differences were statistically significant. The results of studies reviewed by Sutherland’s group varied because the studies used several different strategies, curriculum, and assessment system for training of participants. In the current surgical training system, surgical trainees are assessed only by written, oral, and clinical examinations. All of these examinations assess knowledge, decision-making, and attitudes (cognitive and effective domains) but do not make any attempt to assess surgical skills (psychomotor domain). The only (formative) assessment of surgical skills carried out in each year of training is the informal, subjective assessment by a teacher. This assessment is subjective, of doubtful validity, unreliable, error prone, and far from ideal.17 The McGill Inanimate System for Training and Evaluation of Laparoscopic Skills is an assessment system developed for evaluation of FLS skills. The 5 tasks can be scored objectively for efficiency (time) and precision (penalty). The system has been tested, is reliable and valid, and is currently the most common objective tool for assessment of laparoscopic skills.18 There is a need for more of these types of objective assessment systems in surgery. The aim of a training curriculum should be for a trainee to acquire skills to a predetermined level of proficiency before progression to clinically challenging cases. Simulators are an important part of the curriculum, but not the only component. The curriculum should include not only training on a simulator, the content of the activity, but also an objective measurement of the trainee’s performance. This constitutes knowledgebased learning, a stepwise technical skills pathway, ongoing feedback, and progression toward proficiency goals and better enables transfer to the real environment.19
Future Direction for Simulation Training in Surgery Development of Efficient, Realistic Simulation Models Appropriate for Different Levels of Training The Residency Review Committee for Surgery of the Accreditation Council for Graduate Medical Education stated that by July 2008 all surgery residency programs will be required to have access to a surgical skills laboratory.20 Currently, surgical simulation is in its infancy compared to airline pilot training. Advanced virtual reality simulators are in the development stages; however, validation studies are still lacking and cost remains a significant challenge. Low-fidelity (inexpensive) simula798
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Simulation Training in Surgery Michael Ujiki, MD, FACS, and Jin-cheng Zhao, MD, MS Surgical training consists of developing cognitive, clinical, and technical skills. Current surgical training in the USA is based on the German-style residency training system introduced by Sir William Halsted at Johns Hopkins Hospital in 1889, with an emphasis on graded responsibility, in which the surgical technical skills in the resident programs were traditionally acquired through mentoring.1 However, recent advances in minimally invasive surgical technology, educational and motor skill learning theory, and mounting pressures in the clinical environment have raised questions about the reliance on this approach to teaching technical skills in the young generation of surgeons. Therefore, replication of surgical situations through biological models, such as animals and human cadavers, and more recently, the development of nonbiological simulators housed in training laboratories or centers, have been developed.2
Development of Simulation Training in Surgery Advanced Development of Technology in Surgery Revolutionary technological developments in the area of surgery have provided unprecedented opportunities to create an impact on surgical treatment. The growth and more extensive application of minimally invasive surgical techniques are expected to continue to rise. Therefore, the required performance of relatively complicated technical and intellectual tasks in such an environment present the contemporary surgeons with unexpected and serious challenges during the operations with little or no room for error.3 This has raised concerns regarding patient safety and highlights the need to supplement training outside of the operating room. Similar to airline pilot simulation, practicing technical skills in a controlled, risk-free environment may allow surgical trainees to develop and master surgical maneuvers safely. It also provides a means for objective, standardized assessment of skills performed by the learners.
Dis Mon 2011;57:789-801 0011-5029/2011 $36.00 ⫹ 0 doi:10.1016/j.disamonth.2011.08.018 DM, December 2011
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Although the factors suggested above are essential to simulation training, there are still obstacles to overcome. The performance objectives are still locally established and not clearly defined and standardized. There remains conflict between blocked training time and clinical service responsibilities. Last, validity testing of various skills training methods remain incomplete. To address these issues, it has been proposed that (1) surgical educators must augment established curriculums, (2) a new training paradigm must be developed that emphasizes simulated situations in and out of the operating room, early in the training process, and (3) performance evaluation should be shifted to the simulation environment where such evaluation can be more objective and less risky to the patient.21
REFERENCES 1. 2. 3. 4. 5. 6. 7.
8. 9.
10. 11.
12. 13. 14. 15. 800
Cameron JL. William Stewart Halsted. Our surgical heritage. Ann Surg 1997;225:445-58. Sutherland LM, Middleton PF, Anthony A, et al. Surgical simulation: a systematic review. Ann Surg 2006;243:291-300. Dunkin B, Adrales GL, Apelgren K, et al. Surgical simulation: a current review. Surg Endosc 2007;21:357-66. Glaser BM. Surgical simulation: why now? Retina 2009;29:289-91. Reznick RK, MacRae H. Teaching surgical skills— changes in the wind. N Engl J Med 2006;355:2664-9. Ericsson KA. Deliberate practice and the acquisition and maintenance of expert performance in medicine and related domains. Acad Med 2004;79:S70-81. Southgate WM, Annibale DJ. Simulation training in graduate medical education: a means of traversing a changed and changing landscape. Adv Neonat Care 2010;10:261-8. Scallon SE, Fairholm DJ, Cochrane DD, et al. Evaluation of the operating room as a surgical teaching venue. Can J Surg 1992;35:173-6. Peters JH, Fried GM, Swanstrom LL, et al. Development and validation of a comprehensive program of education and assessment of the basic fundamentals of laparoscopic surgery. Surgery 2004;135:21-7. Derossis AM, Antoniuk M, Fried GM. Evaluation of laparoscopic skills: a 2-year follow-up during residency training. Can J Surg 1999;42:293-6. Feldman LS, Hagarty SE, Ghitulescu G, et al. Relationship between objective assessment of technical skills and subjective in-training evaluations in surgical residents. J Am Coll Surg 2004;198:105-10. Wilson MS, Middlebrook A, Sutton C, et al. MIST VR: a virtual reality trainer for laparoscopic surgery assesses performance. Ann R Coll Surg Engl 1997;79:403-4. Palter VN, Grantcharov TP. Simulation in surgical education. CMAJ 2010;182: 1191-6. Schijven M, Jakimowicz J. Virtual reality surgical laparoscopic simulators. Surg Endosc 2003;17:1943-50. Munz Y, Kumar BD, Moorthy K, et al. Laparoscopic virtual reality and box trainers: is one superior to the other? Surg Endosc 2004;18:485-94. DM, December 2011
16.
17. 18. 19. 20. 21.
Hammoud MM, Nuthalapaty FS, Goepfert AR, et al. To the point: medical education review of the role of simulators in surgical training. Am J Obstet Gynecol 2008;199:338-43. Memon MA, Brigden D, Subramanya MS, et al. Assessing the surgeon’s technical skills: analysis of the available tools. Acad Med 2010;85:869-80. Fried GM, Feldman LS, Vassiliou MC, et al. Proving the value of simulation in laparoscopic surgery. Ann Surg 2004;240:518-25 [Discussion 525-8]. Aggarwal R, Crochet P, Dias A, et al. Development of a virtual reality training curriculum for laparoscopic cholecystectomy. Br J Surg 2009;96:1086-93. Berg DA, Milner RE, Fisher CA, et al. A cost-effective approach to establishing a surgical skills laboratory. Surgery 2007;142:712-21. Haluck RS, Satava RM, Fried G, et al. Establishing a simulation center for surgical skills: what to do and how to do it. Surg Endosc 2007;21:1223-32.
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Development of Simulation Training in Surgery Advanced Development of Technology in Surgery Revolutionary technological developments in the area of surgery have provided unprecedented opportunities to create an impact on surgical treatment. The growth and more extensive application of minimally invasive surgical techniques are expected to continue to rise. Therefore, the required performance of relatively complicated technical and intellectual tasks in such an environment present the contemporary surgeons with unexpected and serious challenges during the operations with little or no room for error.3 This has raised concerns regarding patient safety and highlights the need to supplement training outside of the operating room. Similar to airline pilot simulation, practicing technical skills in a controlled, risk-free environment may allow surgical trainees to develop and master surgical maneuvers safely. It also provides a means for objective, standardized assessment of skills performed by the learners.
Dis Mon 2011;57:789-801 0011-5029/2011 $36.00 ⫹ 0 doi:10.1016/j.disamonth.2011.08.018 DM, December 2011
789
Cognitive Theory In surgical training, the learning curve is the process and time during which the learner acquires the motor skills required to adequately perform surgical procedures. Fitts and Posner’s theory of skill acquisition is currently widely accepted in both the motor skills and the surgical literature.4,5 Their theory is composed of 3 stages. In the cognitive stage, the learner intellectualizes the task; performance is erratic, and the procedure is carried out in distinct steps. After repetitive exercises and feedback, the learner reaches the integrative stage, in which knowledge is translated into appropriate motor behavior. Although still thinking about each action, the learner is able to execute the task more fluidly, and with fewer interruptions. In the autonomous stage, action becomes habit, gradually resulting in smooth performance. The learner no longer needs to think about how to execute a particular task and can concentrate on other aspects of the procedure. This model has obvious implications for surgical training. Early stages of learning technical skills take place outside of the operating room; practice is the rule until automaticity in basic skills is achieved. Finally, mastery of basic skills allows trainees to focus on more complex issues, both technical and nontechnical, in the operating room. In general, expertise is established through repetitive purposeful practice, and not volume alone.6 Volume does not account for the skill level among practitioners, because variations in performance have been shown among surgeons with equally high volumes. Purposeful practice is a critical process in the development of mastery or expertise of a technical skill. In the current model of surgical training, the operations are complex, and it is difficult for learners to focus on one small component of the skill and procedure. Theoretically, opportunities for purposeful practice can only be achieved in a simulated environment. In the surgical simulation laboratory, the learners focus on a defined task, typically identified by a teacher, to improve particular aspects of performance; the practice can be repeated along with coaching and immediate feedback on performance.
Challenges in Clinical and Operating Room Environments Clinical situations in surgery have changed dramatically, with increasingly complex procedures, work hour restrictions, and patient safety concerns.7 These situations result in diminished teaching time and have forced surgical educators to find alternative ways to train residents. This 790
DM, December 2011
is especially true in minimally invasive surgeries, which are technically complex and require advanced laparoscopic skills. Patients in teaching hospitals are generally much sicker and have more complex problems than in the past. The increasing complexity of cases and a greater emphasis on mitigating medical error limit the faculty’s latitude in assisting residents with technical procedures. Sheer volume of exposure is the hallmark of current surgical training.8 However, as opportunities for learning through work with “real” patients have diminished, interest in laboratories with specifically designed formal curricula has gradually incorporated into an important model of surgical education, in which basic surgical skills, specific techniques, and some procedures are learned and practiced on models and simulators, with the aim of better preparing trainees for the operating room experience.7,8
Current Status of Simulation Training in Surgery The field of surgical simulation is rapidly evolving and consists of development of simulation models, curriculum, and assessment. A wide variety of models are available for teaching surgical technical skills. These range from high-fidelity models, such as training on animal models, to virtual reality simulators, and lower fidelity video trainer boxes. A trainer box is rather simple and includes a box with slits on the top for laparoscopic trocar insertion. Real laparoscopic instruments are inserted through the trocar into the box. A camera inside the box provides video output to a monitor, on which trainees can watch their own movements. This model can simulate a variety of skills and techniques, including basic laparoscopic instrument handling, transferring objects, cutting, suturing, knot-tying, and clip-applying, through which brain, eye, and hand coordination can be built. The limitation of the trainer box is that it simulates only certain surgical skills rather than an entire operation. The Fundamentals of Laparoscopic Surgery (FLS) Program was first established at the National Meeting of the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) in 2004. FLS is a comprehensive, CD-ROM-based educational curriculum for laparoscopic surgery designed to teach the physiology, fundamental knowledge, and technical skills required in laparoscopic surgery. FLS has 3 parts: a CD-ROM study guide, a laparoscopic trainer box, and an assessment component.9 The FLS trainer box is now used for required training for all graduating surgical residents and was chosen because it is inexpensive, portable, and reproducible (Fig 1). Moreover, the optical system and instrumentation used are similar to those used in the operating room. DM, December 2011
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FIG 1. FLS box setup. A digital video camera is installed inside the trainer box so that no scope is needed. The camera can be connected to laparoscopic tower monitor, TV monitor or laptop for viewing. Two laparoscopic ports are inserted. (Color version of figure is available online.)
The FLS program consists of 5 exercises to develop manual laparoscopic skills: peg transfer (Fig 2), pattern cutting (Fig 3), loop ligation (Fig 4), extracorporeal (Fig 5A), and intracorporeal (Fig 5B) knot-tying. An instructional CD-ROM video demonstrates each exercise in a “‘watch and do’” manner. These exercises are non-procedure-specific and are designed to improve the technical facility of a basic laparoscopic skills set. Once a trainee feels that he or she has mastered these 5 skills, an examination to test competency is available at either an approved testing center, the annual SAGES meeting, or the trainee’s own institution if the hospital has purchased the educational package. SAGES has worked hard to validate FLS training and assessment. A high inter-rater reliability and test–retest reliability have been demonstrated with correlation coefficients 792
DM, December 2011
FIG 2. FLS task 1, peg transfer. This requires trainee to lift the six objects with a Maryland dissector or grasper in the non-dominant hand, transfer midair to another Maryland dissector or grasper in the dominant hand. Then place each object on the other side of the board. Once the transfer is completed, the process is reversed. (Color version of figure is available online.)
FIG 3. FLS task 2, precision pattern cutting. This exercise requires trainee to cut out a circle from a square piece of gauze suspended between clips. (Color version of figure is available online.)
of 0.99 and 0.89, respectively.9 Further validity has been demonstrated with residents at different levels of training showing progressive improvement in their scores.10 More significantly, surgeons who are highly rated on their technical skills in the operating room have higher FLS scores than those who perform poorly.11 DM, December 2011
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FIG 4. FLS task 3, placement and securing of ligating loop. The trainee is required to place a pre-tied ligating loop or endoloop around a tubular foam appendage on the provided mark. (Color version of figure is available online.)
The careful creation and implementation of the FLS program make it the first available education training curriculum in laparoscopic surgery that not only teaches technical skills but also provides educational content, all in a highly validated simulation package. The use of a box-trainer allows this model to be easily distributed and administered, and the cost is acceptable. To make use of the box-trainer even easier, a company named Simulab Corporation from Seattle, Washington (http:// www.simulab.com) has created SimuVision, a boom-mounted digital camera that has the look and feel of a real laparoscope but connects to a laptop or personal computer rather than a video monitor. This allows for the creation of a portable simulated environment that uses an optical system and real surgical instruments the trainee can even take home. Alternatively, computer-based virtual-reality simulators with combined metric systems, such as MIST-VR (Minimally Invasive Surgery Trainer– Virtual Reality), is used to provide feedback to novice learners during practice. The acceptable cost and quantification of performance of the early version provides an alternative tool for surgical training in addition to the trainer box (Fig 6).12 The fidelity of virtual reality simulators range widely, from MIST-VR to systems that teach component procedural skills and replicate entire operations. Such systems allow for practice at variable levels of difficulty, can simulate complications, and automatically provide objective measures of assessment, allowing for both formative and summative trainee 794
DM, December 2011
FIG 5. (A) FLS task 4, extracorporeal suturing. This task requires trainee to place a simple stitch through two marks in a longitudinally slit Penrose drain. Then the knot is tied extracorporeally using a knot pusher to slide the knot down. The knot must be tied tightly enough to close the slit in the drain. (B) FLS task 5, intracorporeal suturing. This task requires trainee to place a simple stitch through two marks in a longitudinally slit Penrose drain using needle holder or Endo-stitch and tie the knot intracorporeally. The knot must be tied tightly enough to close the slit in the drain. (Color version of figure is available online.)
assessment. The trainee’s performance can be monitored and recorded in an exportable database; more importantly, student curricula can be custom designed, and a Web-enabled platform allows for remote administration.13,14 Some more complex virtual-reality computer-based simulators have haptic features that allow for man–machine interface and a realistic sense of touch. Some are even more sophisticated and provide a DM, December 2011
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FIG 6. MIST-VR, a computer-based virtual-reality simulator. (Color version of figure is available online.)
graded response that allows for differentiation from structure to structure, degree of pushing against a structure, and the sensation of pulling, stretching, spreading, and the like.3 However, the advanced computer-based simulators are not popular because of cost ($36,000-$80,000, plus $8000-$15,000 annual service fee) and because of haptics that are still far from reality. Additionally, some studies show that virtual reality simulators are no better than a video-cart system in training novices in laparoscopic skills.15 Virtual reality simulators cannot yet replace animal models and human cadavers when it comes to surgical training. The advantages of animal models include a more realistic environment, and opportunities to mimic intraoperative complications, such as hemorrhage. However, there are many disadvantages to the use of animals, including cost, anatomical differences with humans, and their ethical use.16 Human cadavers are used, but have several disadvantages as well, including cost, limited availability, and an inability to simulate certain intraoperative complications, such as bleeding.13 Sutherland et al performed a systematic review of 30 studies on surgical simulation in the literature. Simulation training was divided into 4 types: 796
DM, December 2011
computer, video, model, and cadaver. These 4 methods of simulation training were compared to each other as well as to standard surgical training in the article.2 The following is a summary of these comparisons. Computer Simulation vs No Training. Learners who trained on computer simulators performed better than those who received no training at all. Computer Simulation vs Standard Training. When computer-simulator-trained students were compared with students who received standard training (eg, surgical drills), the superiority of computer simulation was less pronounced than for “no training” comparisons. The computer simulation vs “standard” training comparisons varied, potentially confounded by the different components of “standard” training, as well as by the different intensities of time allowed on the simulator in the computer simulation groups. Computer Simulation vs Video Simulation. Computer simulation showed mixed results, superior in some studies, but not others, and was inferior to video simulation in one study. This may have depended on types of tasks, with computer simulation producing better results for tasks, such as incisions, but not for knot-tying times. However, there were too few studies to determine this. Computer Simulation vs Physical Trainer or Model. One study showed computer simulation training to be superior to training on a physical trainer. Two or More Types of Computer Simulation: MIST-VR. One randomized controlled trial showed that more demanding training may lead to better performance of surgical tasks on MIST-VR. Another randomized controlled trial failed to show clear differences between massed and distributed practice on MIST-VR. Video Simulation vs No Training. Video simulation groups did not show consistently better results than groups who did not receive training. Video Simulation vs Other Forms of Training. No differences were seen between video box training and other forms of training, such as bench models or standard training. Physical or Model Simulation vs Other Forms of Training, Including No Training. These comparisons showed mixed results; model training may be better than no training and standard training, such as instruction from mentors or manuals. Cadaver Training vs Standard Training. The cadaver-trained group received better scores than the standard training group, who learned independently from the manuals, for the global assessment of operative performance on cadavers (66.5 vs 51.5) and the checklist score (69.5 vs DM, December 2011
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60.5), although it was not stated whether these differences were statistically significant. The results of studies reviewed by Sutherland’s group varied because the studies used several different strategies, curriculum, and assessment system for training of participants. In the current surgical training system, surgical trainees are assessed only by written, oral, and clinical examinations. All of these examinations assess knowledge, decision-making, and attitudes (cognitive and effective domains) but do not make any attempt to assess surgical skills (psychomotor domain). The only (formative) assessment of surgical skills carried out in each year of training is the informal, subjective assessment by a teacher. This assessment is subjective, of doubtful validity, unreliable, error prone, and far from ideal.17 The McGill Inanimate System for Training and Evaluation of Laparoscopic Skills is an assessment system developed for evaluation of FLS skills. The 5 tasks can be scored objectively for efficiency (time) and precision (penalty). The system has been tested, is reliable and valid, and is currently the most common objective tool for assessment of laparoscopic skills.18 There is a need for more of these types of objective assessment systems in surgery. The aim of a training curriculum should be for a trainee to acquire skills to a predetermined level of proficiency before progression to clinically challenging cases. Simulators are an important part of the curriculum, but not the only component. The curriculum should include not only training on a simulator, the content of the activity, but also an objective measurement of the trainee’s performance. This constitutes knowledgebased learning, a stepwise technical skills pathway, ongoing feedback, and progression toward proficiency goals and better enables transfer to the real environment.19
Future Direction for Simulation Training in Surgery Development of Efficient, Realistic Simulation Models Appropriate for Different Levels of Training The Residency Review Committee for Surgery of the Accreditation Council for Graduate Medical Education stated that by July 2008 all surgery residency programs will be required to have access to a surgical skills laboratory.20 Currently, surgical simulation is in its infancy compared to airline pilot training. Advanced virtual reality simulators are in the development stages; however, validation studies are still lacking and cost remains a significant challenge. Low-fidelity (inexpensive) simula798
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Simulation Training in Surgery Michael Ujiki, MD, FACS, and Jin-cheng Zhao, MD, MS Surgical training consists of developing cognitive, clinical, and technical skills. Current surgical training in the USA is based on the German-style residency training system introduced by Sir William Halsted at Johns Hopkins Hospital in 1889, with an emphasis on graded responsibility, in which the surgical technical skills in the resident programs were traditionally acquired through mentoring.1 However, recent advances in minimally invasive surgical technology, educational and motor skill learning theory, and mounting pressures in the clinical environment have raised questions about the reliance on this approach to teaching technical skills in the young generation of surgeons. Therefore, replication of surgical situations through biological models, such as animals and human cadavers, and more recently, the development of nonbiological simulators housed in training laboratories or centers, have been developed.2
Development of Simulation Training in Surgery Advanced Development of Technology in Surgery Revolutionary technological developments in the area of surgery have provided unprecedented opportunities to create an impact on surgical treatment. The growth and more extensive application of minimally invasive surgical techniques are expected to continue to rise. Therefore, the required performance of relatively complicated technical and intellectual tasks in such an environment present the contemporary surgeons with unexpected and serious challenges during the operations with little or no room for error.3 This has raised concerns regarding patient safety and highlights the need to supplement training outside of the operating room. Similar to airline pilot simulation, practicing technical skills in a controlled, risk-free environment may allow surgical trainees to develop and master surgical maneuvers safely. It also provides a means for objective, standardized assessment of skills performed by the learners.
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Although the factors suggested above are essential to simulation training, there are still obstacles to overcome. The performance objectives are still locally established and not clearly defined and standardized. There remains conflict between blocked training time and clinical service responsibilities. Last, validity testing of various skills training methods remain incomplete. To address these issues, it has been proposed that (1) surgical educators must augment established curriculums, (2) a new training paradigm must be developed that emphasizes simulated situations in and out of the operating room, early in the training process, and (3) performance evaluation should be shifted to the simulation environment where such evaluation can be more objective and less risky to the patient.21
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Hammoud MM, Nuthalapaty FS, Goepfert AR, et al. To the point: medical education review of the role of simulators in surgical training. Am J Obstet Gynecol 2008;199:338-43. Memon MA, Brigden D, Subramanya MS, et al. Assessing the surgeon’s technical skills: analysis of the available tools. Acad Med 2010;85:869-80. Fried GM, Feldman LS, Vassiliou MC, et al. Proving the value of simulation in laparoscopic surgery. Ann Surg 2004;240:518-25 [Discussion 525-8]. Aggarwal R, Crochet P, Dias A, et al. Development of a virtual reality training curriculum for laparoscopic cholecystectomy. Br J Surg 2009;96:1086-93. Berg DA, Milner RE, Fisher CA, et al. A cost-effective approach to establishing a surgical skills laboratory. Surgery 2007;142:712-21. Haluck RS, Satava RM, Fried G, et al. Establishing a simulation center for surgical skills: what to do and how to do it. Surg Endosc 2007;21:1223-32.
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