Endoscopic Simulators

Introduction

Safe performance of gastrointestinal endoscopic procedures requires extensive and high-quality training. Endoscopy skills have traditionally been taught within the clinical setting, in the form of a mentor-apprenticeship model in which novice endoscopists learn skills under the supervision of experienced preceptors. Concerns with regard to patient safety and training efficiency have prompted the endoscopy community to reconsider this training model. It is becoming increasingly less acceptable that endoscopic techniques are learned entirely in the clinical setting before trainees have shown some proficiency in their skills in a safe, controlled, simulated training environment.

Several factors have contributed to the shift toward incorporation of simulation into gastrointestinal endoscopy training. First, recent guidelines from endoscopy focused organizations such as the American Society for Gastrointestinal Endoscopy (ASGE) have encouraged the use of simulation-based training, and it is now mandated by accreditation organizations in certain jurisdictions such as the United States. Secondly, whereas the “ideal” training platform has traditionally been considered the patient, gastrointestinal endoscopy is uniquely challenging to teach in the clinical environment, as preceptors are required to relinquish complete control of the endoscope to allow trainees to learn the technique. Clinical training also adds time to each procedure, which has implications with regard to capacity and economics. Additionally, clinical demands and time restrictions often limit a preceptors' capacity to provide detailed instruction and feedback. Furthermore, training on patients occurs through chance encounters, which may limit exposure to particular pathologies. Finally, concern for patient comfort and safety can often impact the learning experience and act to limit case availability and training exposure, especially for certain higher risk procedures such as endoscopic retrograde cholangiopancreatography (ERCP).

There are also a number of recognized benefits of endoscopic simulators that have helped drive their integration into training. Simulators provide learners with the opportunity to practice cognitive, technical, and integrative competencies related to endoscopy in a controlled environment. Learners can build a framework of basic techniques through sustained deliberate practice in a setting where errors can be allowed to progress so trainees can learn from their mistakes without adverse consequences. For novice learners, mastery of basic skills in a low-risk controlled environment, prior to performance on real patients, enables trainees to then focus on more complex skills once they progress to clinically-based training. Simulation also permits individualized learning, as cases can be adapted to a learner's unique needs and the nature and difficulty of the simulation tasks can be systematically varied over time to adapt to the skill level of the learner. Additionally, trainers do not have to juggle teaching and clinical demands and can instead focus solely on learners to provide a learner-centered educational experience and take full advantage of learning opportunities without distraction. Simulation can also be used to expose learners to patient pathophysiology or techniques (e.g., variceal banding) that might be rarely encountered in the clinical setting. In addition, the hands-on lab affords trainees with an optimal opportunity to develop critical communication skills needed to perform procedures that require coordination with one or more assistants. Finally, simulators can play a potential role in maintaining skills for practicing physicians who perform fewer endoscopic procedures or have taken a break in their training and/or practice.

Despite the shift towards simulation-based training and the potential benefits of simulation, a 2014 survey revealed that less than half of adult gastroenterology programs in the United States utilize simulation and it is mandated in only 15% of programs. Across programs, simulation is being employed in a markedly heterogeneous fashion with regard to the manner in which it is integrated into training, the time spent on simulators, and the training tasks and types of simulators employed. Additionally, whereas program directors widely recognize the role that simulation can play with regard to assessment, no programs directors reported using simulation to assess endoscopic competence.

As outlined in the ASGE's 2012 Preservation and Incorporation of Valuable Endoscopic Innovations (PIVI) report, the decision about whether to incorporate simulation technologies into endoscopy training must rely on data regarding the magnitude of training benefits, any cost savings resulting from accelerated learning, associated expenses, and training needs. The use of simulation within a training curricula needs to be justified and outweigh the associated costs. The rationale for using simulation should be based on evidence with regard to the potential benefits for patients, trainees, preceptors, and training programs.

With regard to upper endoscopy and colonoscopy, extensive systematic reviews on the topic have shown endoscopy simulation-based training to be beneficial for novice endoscopists in developing knowledge and technical skills in a safe and controlled environment, prior to clinical practice. Existing randomized control trials (RCTs) have primarily shown benefit during the early phase of clinical work and potential benefit in shortening the learning curve to competency; however, a reduction in the learning curve of more than 25%, as proposed in the ASGE's PIVI report as a threshold for widespread adoption to their use, has yet to be demonstrated. Additionally, diagnostic and therapeutic gastrointestinal endoscopy skills learned within the simulated setting have been shown to transfer to patient care. To date, there is little evidence that patients benefit materially with regard to factors such as adverse events or satisfaction when a procedure is performed by a trainee with previous simulator experience. Potential cost and manpower reductions resulting from simulation training have also not been examined in depth. Additionally, validated models for training more advanced therapeutic procedures such as polypectomy and stenting are lacking or sparse.

Whereas evidence to date suggests that simulation-based endoscopy training is effective and learning outcomes transfer to the clinical setting, simulation must be integrated into training and assessment in a thoughtful and purposeful manner to maximize its benefit. This chapter will outline factors to consider in choosing an appropriate simulator for training, elaborate on the use of simulation to train endoscopic nontechnical skills, discuss instructional design features that can be used to enhance endoscopic training using simulators, and outline the potential use of simulation for assessment of endoscopic competence. The value of simulation for basic endoscopy training and details of available simulator models for specific procedures have been reviewed extensively elsewhere and will not be discussed in depth.

Choice of Simulators in the Training Environment

Traditionally educators have favored high-fidelity computerized simulators for teaching technical skills based on the assumption that they provide the optimal context to prepare learners for the clinical environment. However, this assumption is not based on empirical data. Over the past decade, the capabilities of endoscopic simulators have steadily expanded. Currently, there are a wide variety of simulators available to teach endoscopy and one's choice of simulator should be based on the educational and/or assessment goals, as well as cost, as opposed to technology. Effective use of simulation is highly dependent on a close match of educational goals with simulation tools.

The use of simulation to teach gastrointestinal endoscopy dates back to the 1960s. In general, there are five types of endoscopic simulators: (1) inanimate static models or mechanical simulators, (2) virtual reality computer generated models, (3) ex vivo (explanted organ) animal models, (4) live animal models, and (4) hybrid simulations. Every training model has its advantages and disadvantages and is best suited to training specific tasks and levels of learners ( Table 13.1 ). Inanimate static models or mechanical simulators are part-task trainers that generally involve performance of characteristic motor tasks with a real endoscope within an inanimate closed environment with realistic visual and motor requirements and haptic feedback. They generally do not provide summative feedback like some computerized endoscopy simulators do; therefore, a mentor must be present to guide training. However, they are inexpensive, portable, and allow for deconstruction of specific tasks such as retroflexion, torque steering, and tip control. Virtual reality computerized simulators, which became commercially available in the 1990s, are advantageous in that many are capable of providing real-time feedback and a library of clinical cases with varying degrees of difficulty of anatomy and complexity of tasks. Whereas the virtual reality computer simulators incorporate pathology recognition, the relative value of simulator training in this core component of competency, as compared to didactic resources (e.g., web-based atlases, lectures) in combination with mentored clinical endoscopy experience, has not yet been determined. Additionally, virtual reality simulators are costly and not easily portable. Ex vivo (explanted) models are fabricated from a combination of plastic parts and explanted animal organs which can be used to train specific tasks such as endoscopic mucosal resection (EMR), ERCP, or hemostasis techniques. Live animal models (e.g., anesthetized porcine model) are the most realistic endoscopy simulators. Although the haptic feedback closely resembles human tissue, there are distinct differences with regard to wall thickness and organ orientation, resulting in a slightly different “feel.” Animal models in general are difficult to prepare and use. They require procurement of animals and/or animal organs, extensive preparation and disposal processes, use of animal-use endoscopes, and they cannot be used indefinitely. Ex vivo models have the advantage of being easier to assemble, more affordable, and raising less ethical issues when compared to use of live animals; however, they have unfavorable tissue characteristics compared with vital tissue. Due to the aforementioned limitations, many endoscopy training programs do not use these simulator models locally and they are most often employed at specially equipped regional or national training courses or meetings. Finally, hybrid simulation links a simulated patient (i.e., an actor) with a computer-driven virtual reality simulator or inanimate model in a simulated clinical environment. It is advantageous in that it allows learners to perform endoscopic procedures in a holistic clinical context without risk of causing harm. Additionally, multidisciplinary team members, such as an endoscopic nurse and/or anesthesiologist, can participate in scenarios to facilitate training of integrative competencies related to endoscopy, such as situational awareness, professionalism, and communication. Integrative competencies are higher-level competencies required to perform an endoscopic procedure that complement an individual's technical skills and clinical knowledge to facilitate effective delivery of high-quality endoscopic care in varied contexts. Integrative competencies include core skills, such as communication and clinical judgment, that allow individuals to integrate their knowledge and technical expertise to function effectively within a health care team, adapt to varied contexts, tolerate uncertainty, and ultimately provide safe and effective patient care.

As mentioned previously, educational goals, and not technology, should guide decisions about which simulator to use for training and assessment. Certain simulators, such as virtual reality computer generated models and live animal models, are useful to teach performance of the procedure as a whole, whereas education in basic endoscopic procedural elements, such as video image interpretation, endoscope handling, and torque steering, can be delivered using simple and less expensive inanimate part-task trainers. Becoming familiar with the endoscope and learning a procedure at the same time creates increased cognitive work load and slows skills acquisition. Pretraining on a mechanical simulator until a certain level of proficiency is reached may help shorten the learning curve and better protect patients. Part-task simulators (including mechanical and ex vivo models) are useful to teach and/or reinforce particular skill sets or components of the procedure, such as polypectomy or bleeding control, as they deconstruct the skill set, allowing the learner to focus on the task at hand. Finally, more complex clinical events and behaviors, such as team training, benefit from use of more sophisticated hybrid simulations which involve use of inanimate or computerized simulators in conjunction with simulated patients (see the section entitled, Simulation to Train Endoscopic Nontechnical Skills).

In deciding which simulator one should use for a given training goal or stage of training, one should consider both the capabilities of the simulator itself and the training program that will be used to support the model. Simulators can be used to teach and/or reinforce multiple training tasks depending on how they are integrated within a curriculum. Ultimately, the choice of simulator(s) must reflect the desired educational goals. We propose a three-stage framework for endoscopy simulation-based training that can be applied to help select simulators for a comprehensive endoscopy curriculum. The framework encompasses (1) task deconstruction using part-task trainers, followed by (2) use of simulators suited to whole procedural training and finally, (3) use of hybrid simulation to train higher-level integrative competencies related to endoscopic nontechnical skills. This framework is theoretically in line with a progressive model of simulation-based training which is outlined in the following section. As mentioned previously, the utility of various simulators for specific training tasks is detailed in Table 13.1 .

Progressive Model of Simulation-Based Training

Progressive learning, which involves planned and gradual increases in the difficulty or complexity of simulation-based tasks as learners' abilities improve, can be used by educators to guide selection of simulators for educational programs. In this way instruction is matched to the learner's developmental level and simulators are chosen based on their ability to train a specific task. Range of task difficulty can be varied longitudinally across a curriculum or within a single session. An example curriculum for endoscopy that is based on the progressive model of simulation-based training could start trainees on a low-fidelity, bench-top colonoscopy simulator which is ideal to teach basic endoscopic skills with regard to interpretation of the video image, endoscope handling, and torque steering ( Fig. 13.1 ). A virtual reality simulator could then be used to teach leaners various strategies for endoscope advancement (e.g., loop reduction, patient position change), pathology recognition, and basic biopsy and polypectomy technique. Subsequently, ex vivo animal tissue models could be used to train more advanced techniques such as EMR, or hemostasis skills including injection, electrocoagulation, and hemoclip application. This model of progressive simulation-based training has been used within the field of aviation with success. In aviation training, as the situations grow more complex, trainees are increasingly required to troubleshoot difficult and unexpected situations. By analogy, particularly with the ex vivo models and hybrid simulation, and to an extent with difficult anatomy cases on the virtual reality simulator, progressive challenges can be created and trainees may be tasked to manage an unplanned adverse event in the controlled environment of the hands-on lab.

A recent RCT by Grover et al (2017) within the field of gastrointestinal endoscopy has shown that a progressive simulation-based training curriculum that involves a deliberate transition from low to high task complexity and task difficulty improves colonoscopy skill acquisition and transfer to the clinical setting, compared to a curriculum utilizing high-fidelity simulation in isolation. It is thought that progressive simulation-based training is effective as task difficulty is adapted to align with the current skill of the learner, thus allowing learners to be optimally challenged as their skills improve; this is a factor known to enhance learning and promote task engagement. As learners progress through training they can build upon previously attained competencies by engaging in activities of increasing difficulty without being cognitively overloaded. The aim is to train learners on progressively more challenging and difficult tasks that do not result in overwhelming the trainee in terms of cognitive load.

Simulation to Train Endoscopic Nontechnical Skills

Use of simulation enables learners to practice and receive feedback in a safe, learner-centered environment. Simulation can be used to improve not only competence of endoscopic technical skills but also cognitive and integrative skills such as teamwork and decision-making. Over the past decade there has been increasing recognition of the importance of endoscopic nontechnical skills (ENTS). In addition to the knowledge and technical skills required to perform endoscopy safely and proficiently, nontechnical skills play a central role in high-quality endoscopic practice. The vast majority of recommendations stemming from a report by the National Confidential Enquiry into Patient Outcomes and Death, which investigated deaths occurring within 30 days of adult therapeutic gastrointestinal endoscopy procedures in the United Kingdom, highlight failings in nontechnical skills and behaviors such as communication, situational awareness, decision making, and teamwork, as opposed to technical skills. Nontechnical skills are an integral facet of competent endoscopic practice and an important contributor to patient safety and clinical outcomes.

Currently there is limited recognition, training or assessment of ENTS within endoscopy training programs. Training with regard to appropriate communication with an endoscopic assistant to coordinate techniques such as wire passage, injection, or polypectomy is often taught using ex vivo or virtual reality endoscopy simulator models. However, such training does not address the full breadth of nontechnical skills related to endoscopy, such as situation awareness. Hybrid simulation is a potential means of effectively training ENTS. Hybrid simulation is a term coined by Kneebone (2003) to describe the process of attaching a simulator to a simulated patient. With regard to endoscopy, hybrid simulation involves a learner performing a procedure on an endoscopy simulator in a naturalistic setting (i.e., endoscopy suite), while interacting with an actor portraying a patient (i.e., a simulated or standardized patient) ( Fig. 13.2 ). Multidisciplinary team members, such as an endoscopic nurse or anesthesiologist, can also be introduced into the scenarios. In this way, aspects of ENTS such as communication, decision making, leadership, teamwork, role clarity, coordination, shared goals, mutual respect, crisis management, and empathy can be taught during the simulations. Incorporation of debriefing that focuses on ENTS into team training allows team members to develop a shared mental model of the team's performance, reflect on their performance, and identify positive and negative aspects of performance to develop a plan for improvement and identify and mitigate causes of errors or near misses. Recently published studies by Grover et al (2015 and 2017) support the use of a curriculum integrating hybrid simulation as a means to improve nontechnical skill acquisition in novice endoscopists and transfer of skills to the clinical environment. Salas et al (2008) have identified evidenced-based principles for effective team training that can be integrated when designing endoscopy simulation-based team training sessions, including: (1) focusing team training on identified critical teamwork competencies; (2) emphasizing teamwork over task work; (3) ensuring training is relevant to the clinical environment; and (4) providing timely, descriptive and relative feedback, which is essential to correct and reinforce desired teamwork behaviors.

Integrating Simulators Into Training

Health professions education has placed increased reliance on simulation in recent decades to enhance learner knowledge, skills, and attitudes, as well as to provide opportunities for practice in a safe and controlled environment. Development of any simulation-based training program should be evidence based, much like the practice of medicine. Integration of instructional design features known to enhance simulation-based instruction are required to optimize transfer of learner skills and behavior to the clinical workplace. Incorporation of these principles would advance the current state of endoscopic simulation-based training and enhance the effectiveness of endoscopy training. The following sections outline several educational principles that may be applied to develop well-designed endoscopy simulation-based training curricula to enhance learning.