How important are simulators for endoscopy training?

The role of simulators for training in endoscopy is an area of some historical uncertainty yet great contemporary opportunity. Determining the importance of simulators requires constant appraisal of their use, and the current limitations of high cost and lack of validated curricula also need to be addressed.

The main focus of early research using virtual reality simulators for endoscopy training was the validity and reliability of the machine, and only recently has learner-centered, evidenced-based research emerged to establish the importance of endoscopic training simulators as instructional and assessment tools. At the time when American surgical educators were articulating the need for flexible endoscopy training to initially take place in a simulated environment, a European Association for Endoscopic Surgery working group, focusing on the evaluation and implementation of simulators and their curricula, established levels of recommendation for the use of flexible endoscopy simulators based on the available evidence of their effectiveness [1] [2]. Evidence of effectiveness, however, was initially mixed, with evidence both for and against the use of simulators in endoscopy training when validation focused on the machine itself. As the validation for simulator and curriculum evolves to focus on the learner rather than the technology, the effectiveness of simulators for endoscopy training is emerging.

An article by Thompson et al. in this issue of Endoscopy introduces a table-top part-task trainer – the so-called TEST box – the validation of which is an example of how learner-centered validation establishes the meaning of task performance for the simulator, and can lead to determinations of simulator effectiveness [3]. The validation of this simulator is defined by expert content analysis of relevance, representativeness, and realism. The validation of the curriculum assigns meaning to the scores produced on the simulator based on the scores produced by users with varying skill levels. This methodology provides a framework for the use of the simulator for trainee assessment, and can establish simulator effectiveness. It is now well accepted across disciplines that removing early endoscopy training from the operational environment offers the ability to increase the number of repetitions and the breadth of complexity that trainees experience within the context of standardized instruction [4] [5]. Yet the worthiness of simulators still relies on high-quality evidence of their educational capabilities, and this has been provided by Thompson et al. for the TEST box.

Simulator use in the delivery of endoscopy training remains hindered by some notable limitations such as high cost and the lack of validated curricula. Initial efforts to use simulators for training in flexible endoscopy relied upon explanted animal tissue, and were limited by their expense and intensive set-up. Computer-based models offered a logical, viable substitute. The most studied of these is the virtual reality simulator – a system that employs a modified version of an endoscope with haptic feedback to simulate the navigation of the gastrointestinal system. Computer-based simulators for flexible endoscopy are expensive. Base models start at US$ 46 000 – 74 000 [6]. Software modules that provide training for specific procedural tasks, such as endoscopic retrograde pancreatography and endoscopic ultrasound, are in the range of US$ 9000 – 20 000 each depending on the manufacturer. A recent cost analysis of one virtual reality endoscopy simulator, undertaken using single institution data based on 10 trainees per year over 5 years, cited a depreciation of approximately $11 000 per year coupled with a per trainee cost of just over $ 1000 per year [7]. There exists the need, therefore, for low-cost, effective simulators. The Thompson et al. article describes a much needed tool for both skill acquisition and assessment of endoscopic trainees. The TEST box is comprised of inexpensive physical elements positioned within a portable yet confined space. The simulator requires learners to demonstrate discrete endoscopic skills to complete the designed task. Such innovations are particularly significant for programs in which the cost of computer-based endoscopy simulators is prohibitive. More longitudinal cost-effectiveness studies of simulators for flexible endoscopy, as well as the development of more inexpensive models, must be undertaken.

Across multiple specialties, comprehensive, validated, simulation-based curricula are lacking. Flexible endoscopy has been no exception. The European Society of Gastrointestinal Endoscopy recommends the use of simulation for training in endoscopic ultrasound and the interprofessional training around the administration of sedation, offering a detailed and validated curriculum in the latter [8] [9]. This year, the Society of American Gastrointestinal and Endoscopic Surgeons released its virtual reality-based endoscopic curriculum – the Fundamentals of Endoscopic Surgery (FES) – to address the curriculum deficit. The FES program is designed to set benchmarks regarding cognitive knowledge and manual skills needed in the foundation of a flexible endoscopy practice [10]. Program validation as an assessment tool has already been evidenced by the strong correlation between scores for the procedural tasks in addition to the total score (which included the cognitive component) and the level of experience [11] [12]. Because the release of FES is so recent, there is currently limited information on how training programs will implement this curriculum or how it will be disseminated beyond a surgical audience. Given that a large number of simulated procedural tasks have not been previously validated, this program represents a move toward validating tasks by correlating them with demonstrated cognitive and technical competency. As suggested by Vapenstad and Buzink, future research must focus on the use of procedural simulators in effective training set-ups and further investigate the ability of procedural simulation to improve clinical outcomes [13].

Simulators are gaining significance in endoscopy training. Their regard as universally useful has been hampered by their high cost and lack of curricula to aid delivery. With the development of learner-centered validation, cost-effective training models, and comprehensive curricula, simulators will emerge as essential endoscopic training tools.

• References

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