Gastrointestinal Endoscopy
Volume 71, Issue 2 , Pages 308-311, February 2010

Computers for colonoscopy training: where do they fit in?

Clinical Professor of Medicine, New York University School of Medicine, New York, NY, USA

Article Outline

Abbreviation: DOPS, Direct Observation of Procedural Skills

 

Virtual reality colonoscopy simulators may enhance the learning process, improve patient comfort, and reduce the time required for labor-intensive expert supervision.

Optimizing training in performing endoscopic procedures constitutes an essential component of the effort to maximize quality in endoscopy. Over the past 10 years, important principles have evolved regarding colonoscopy training. A consensus has come to recognize that sheer numbers of supervised procedures performed does not in itself confer competency.1, 2 There is also a growing recognition that training must be directed to both the technical and cognitive components of the procedure.3 Much benchmarking data have been published that set the bar for how well colonoscopists ought to perform when properly trained, in terms of such variables as cecal intubation rates, perforation rates, and adenoma detection rates on screening examinations.4, 5, 6, 7

Despite these advances, several challenges persist in the area of colonoscopy training. For the near term, although standard optical colonoscopy remains the criterion standard for colorectal cancer screening, manpower needs will require a steady stream of individuals trained to perform this procedure. The potential to reduce the labor-intensive aspects of the training process may become increasingly important to meet the increased demand for training, coupled with reduced available time for those qualified to provide expert supervision. Apart from manpower concerns, there are substantial cost considerations from lost productivity at institutions in which novices are being trained to perform colonoscopy. In a study analyzing data from the Clinical Outcomes Research Initiative project, involvement of fellows prolonged the procedure time by 10% to 37%, with an estimated loss of reimbursement to the academic institution of $500,000 to $1,000,000 per year.8

Computer simulators have been available for several years. Presently, there are two commercially available computer-based simulators of the GI tract: the GI-Mentor, which was developed by Simbionix (Tel-Hashomer, Israel),9 and the AccuTouch, which was developed by Immersion Medical (Gaithersburg, Md).10 The machine used in the study appearing in this issue of Gastrointestinal Endoscopy11 is a new simulator designed in association with the Olympus Corporation exclusively for colonoscopy training based on mathematical modeling.

Both of these simulators use real endoscopes and allow steering and torquing of the instrument, which also has suction and inflation buttons. These devices provide trainees with tactile sensation that mimics an actual endoscopic examination and are loaded with several cases with varying pathological findings and anatomical configurations. For each case, trainees are provided a patient history, including laboratory work-up and imaging studies, before the mock procedure is performed. During the simulated colonoscopies, trainees receive feedback about looping, over-insufflation, and loss of mucosal visualization. Data are collected automatically on various parameters as each procedure is performed. Real-time access to 3-dimensional diagrams of the conformation of the endoscope as loops are formed and reduced is also provided. Accessory channels allow for repeated practice of basic therapeutic interventions such as biopsy and polypectomy. Once the tutorial session is completed by the trainee, instructors can view the recorded events. Comments can be entered in the trainee file, and notes can be sent to the trainee by use of a message facility.

The promise of virtual reality colonoscopy simulators has been that they might enhance the learning process, improve patient comfort, and reduce the time required for labor-intensive expert supervision.

There is a growing body of literature validating the role of computer simulators in teaching colonoscopy. Efforts have been made to establish construct validity by demonstrating improved performance on the models with increasing level of endoscopic expertise. Other studies have observed improved performance on the simulators themselves as evidence of the benefit of the simulator experience. Last, some trials have been conducted to assess the efficacy of training on computer simulators on the performance of actual colonoscopies during the early part of training. Such validation studies provide the strongest evidence that simulators have a benefit in training. Gerson12 has recently reviewed the body of evidence that demonstrates the benefit of using virtual reality computer simulators.

The article by Haycock et al11 that appears in this issue of the Journal adds nicely to the literature demonstrating that intensive practice on virtual reality computer simulators can confer real benefits to the early phase of colonoscopy training.

The methodology used in this study is similar to that used by Gerson and Van Dam13 in a negative study looking at the utility of simulator work in lieu of direct training on patients for the performance of flexible sigmoidoscopy. The assessment of skill in the article by Haycock et al occurred after 16 hours of training either on the simulator or on patients under expert supervision with the use of the ScopeGuide. The simulator training, although not totally unsupervised, involved minimal instructor teaching and feedback. Although it is possible to ascribe some of the improvement on skill measured on the simulator to experience on the particular machine, the equivalent performance on real cases to fellows receiving 16 hours of real procedure experience, using a validated measure of skills assessment, does provide tangible evidence of benefit.

Why did this study show benefit when the Gerson and Van Dam13 study did not? Most likely, this relates to the number of hours spent on the simulator—16 hours in this study as opposed to an average of only 2.3 hours per trainee in the flexible sigmoidoscopy trial. Other explanations are possible, including the fact that this study used a different computer simulator. Both groups here used 3-dimensional imaging during their training phases, so this variable was controlled. The two randomized, controlled trials that have demonstrated a benefit of simulator versus no simulator experience in performance over the early part of the colonoscopy learning process also provided trainees with more time working on the simulator than did the negative flexible sigmoidoscopy study.14, 15 It is interesting that the smaller Mayo Clinic study15 of 6 hours of training led to benefits observed in only up to 30 cases, and in the New York multicenter study,14 significant benefit after 10 hours of simulator work was demonstrated for the first 80 cases. In both studies, the nonsimulator trained group caught up eventually in skill to their nonsimulator-trained counterparts. How much simulator training is optimal? The answer seems to be a minimum of 6 hours to derive any benefit. However, we do not yet know after how many hours of practice the benefit from additional time working on the models diminishes.

The authors in this article highlight potential limitations of their findings. In particular, the UK Joint Advisory Group Colonoscopy Direct Observation of Procedural Skills (DOPS) assessment form and the global score, although validated assessment tools, were designed to determine competency in colonoscopy for individuals who have completed their training. In this study, the DOPS and global score were used to assess skill after 16 hours of training on 3 test cases. Even though they were not designed to measure interim skill during training, these instruments are rigorous objective measures.

The potential to replace the initial 16 hours of real-patient-based teaching with independent work on a machine is quite attractive for patients and busy instructors alike. The present article suggests that an intensive independent experience on the computer simulator might allow trainees to essentially start their learning process on real examinations at the skill level equivalent of having completed the first 16 hours of supervised training. We are told that this amounted to at least 8 real colonoscopies, but the mean number of cases actually performed before testing was not stated. How big a difference this signifies in practical terms from the instructor time perspective depends on whether the total number of hours of supervised colonoscopy before achievement of competency will be reduced by virtue of the initial computer training; because the learning curves of participants in this trial were not followed to this endpoint, this cannot be determined from the data presented. It would be most interesting to know how the simulator-trained group performed after their next 16 hours of real colonoscopy experience, compared with the control arm after their first 16 hours. More importantly, what will be the median number of cases before the DOPS testing or global scores confirm competency for each group? In the New York study of 45 trainees,14 despite the significant improvement for the first 80 cases, ultimately the median time to competency did not differ between the two groups. In order to really save any instructor time or money, the simulator experience needs to significantly impact this variable.

Although this article did not show patient satisfaction data, others have shown that simulator pretraining had positive effects on patient comfort during colonoscopies performed by trainees.16 However, the New York multicenter trial13 showed no difference in proctor assessment of patient discomfort during the procedures, despite the objective differences in trainee skill observed during the first 80 cases.

Several issues regarding simulators remain unresolved. Does ongoing work on the simulator during the phase of actual patient-based, supervised colonoscopy have any complementary benefit? Does instructor feedback during simulator work further increase the benefit on the learning process, albeit at the expense of ceding the benefit of freeing up instructor time? Mahmood and Darzi17 published a study looking at 26 doctors of varying experience performing simulated colonoscopies on the Immersion simulator, in which the participants failed to show improvement on the simulator during 5 repeated attempts on the same procedure in the absence of feedback. In contrast, the studies showing benefit from simulator work on actual colonoscopy performance, including the work of Haycock et al, involved trainees whose simulator time was largely unproctored.11, 14, 15

As the authors point out, simulators also have untapped potential to improve nontechnical aspects of colonoscopy performance among trainees, such as pathology recognition, correct identification of lesions, and completeness of withdrawal. The multicenter, randomized comparison of simulator to no simulator experience before performance of real colonoscopy demonstrated significant improved frequency of competent examinations during the first 80 cases by using a measure that did require both technical and cognitive success.14 However, the ability of simulator training to enhance real pathology recognition or adenoma detection rates among trainees has not yet been specifically evaluated. Although the various commercially available models all contain modules replete with varying pathological findings, the interactive experience on the machines, to date, has not fully taken advantage of computers' capability for real-time quizzing. The addition of such activities to the technical practice—the focus of most of the simulator work to date—would ensure that trainees get repetitive experience noting all abnormalities, defining what they see, and receiving automatic immediate feedback.

As for therapeutic intervention training, there likewise has been no validation, to date, for the computer simulators. Moreover, it will be difficult to improve on the growing capability of ex vivo animal tissue models, which can allow for the deliberate practice of many therapeutic interventions such as polypectomy, injection techniques, hemostasis techniques, stent deployment, and closure of defects with clips.18, 19

Although computer simulation for colonoscopy training has come a long way, and the work by Haycock et al11 has reinforced the evidence that they can have a significant impact for novices, two major challenges must still be overcome before these simulators can have a wider role in colonoscopy education. First, the cost issue remains an important obstacle. Only when investigators can demonstrate actual savings by way of reduced instructor time for training or quicker acquisition of competency would the sizable outlay for each simulator unit be justified by teaching institutions. This certainly holds true for most gastroenterology training programs that are abundant in volume of cases that need to be performed, if not always as abundant in time of available expert instructors. However, for others' programs, such as surgical departments in which case volume may be the limiting factor for training, simulators may indeed play an increasing role in colonoscopy training despite the cost. At present, mobility is an issue hindering the feasibility of sharing simulator units among institutions that are not geographically close. It remains unclear whether such good results from simulator training would be achieved if lower-cost, less-realistic simulators were used or if, because of sharing, limited time were available per trainee to get hands-on practice.

The second challenge may actually solve the issue of cost if it can be overcome. Many simulators have shown construct validity in initial trials, distinguishing performance on the simulator between novices and experts.20, 21 However, what is really needed is a validated, simulator-based assessment that is predictive of competent performance on actual colonoscopies. Investigators such as Haycock et al are working to achieve such a reliable way to use simulators not just to train but also to evaluate skill. Once this can be done, this will greatly broaden the appeal and value of computer simulators to hospitals responsible for credentialing individuals to perform colonoscopy. If this were to occur, virtual reality simulators would become more readily available at these institutions for teaching purposes as well. Because of the evidence provided by this study and others before it, once the simulators are made available to trainees, they should become an integral part of novice training.

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Disclosure 

The author disclosed the following financial relationships relevant to this publication: He is a speaker for Olympus Corp, USA and is on the animal tissue training models advisory board for Endosim, Inc.

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References 

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PII: S0016-5107(09)02534-6

doi:10.1016/j.gie.2009.09.025

Gastrointestinal Endoscopy
Volume 71, Issue 2 , Pages 308-311, February 2010

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