The Use of Simulators for Training in GI Endoscopy

Quality management and optimal patient care are two of the most important issues in clinical medicine today. While evidence-based medicine is rapidly becoming the “gold standard” for treatment modalities, the responsibility for education, including theoretical background as well as acquisition and refinement of manual skills in gastrointestinal endoscopy, remains in the hands of the individual physician. New endoscopy simulators have rekindled the discussion as to whether it is preferable for training in basic manual skills to take place away from the patient [1].

The paper of Ferlitsch et al. from Vienna, published in this issue of Endoscopy, shows that the use of a simulator could or should form part of future education in diagnostic gastroscopy and colonoscopy. Included in the study were 13 beginners and 11 experts. After a short introductory session on the simulator, all participants were evaluated in a baseline assessment. This included the diagnostic steps of a virtual gastroscopy and colonoscopy procedure, and two modules concerned with endoscopic dexterity and skills, called “Endobasket” and “Endobubble.” The beginners were then divided into two groups, with seven participants in an intensive training group and six in a control group. This was followed by a 3-week training program of 2 hours of simulator practice daily for 5 days a week, which was offered only to the intensive training group. After 3 weeks the intensively trained group performed significantly better using the simulator than the untrained group, and reduced the initial difference from the expert group to a nonsignificant level.

The authors took a simple but important step in the validation of the Symbionix computer simulator as a teaching tool [2] [3]. Experts did better than beginners in the gastroscopy and colonoscopy procedures, as well as in the two virtual skills test modules. The higher performance level of the experts demonstrated the simulator’s ability to identify specific quality aspects of the endoscopic procedure. Prior experience in computer games, age, and sex did not have any influence on the result. The study is published in parallel with one described in the June 2002 issue of Surgical Endoscopy [4]. This was carried out using a second type of endoscopy simulator, the “PreOp” of the Immersion Medical Corporation, USA. The authors, from London, also studied the correlation between clinical endoscopic competence in the beginners’ state and judgement given by the computer simulator. The participants had to perform a virtual flexible sigmoidoscopy procedure using the simulator. The percentage of colonic mucosa visualized, the time taken, and the path length of endoscope travel were measured. The 45 participants were divided into three groups: novice (no lower gastrointestinal endoscopy ever performed); intermediate (5 - 50 clinical examinations performed); and trained (more than 200 examinations). There was a significant difference between all three groups with respect to percentage of mucosa visualized and efficiency ratio (% mucosa/time). The novice group was slower and had a longer path length of instrument travel compared with the others. The authors concluded that the “PreOp” virtual reality simulator is a valid discriminator of flexible sigmoidoscopy experience.

Unfortunately the study by Ferlitsch et al. lacks a clinical stage, with surveillance of untrained and simulator-trained participants during their first experiences with real patients; this should follow in a subsequent trial soon. As in previous studies [3], the authors mention some limitations of the simulator. The most difficult part of a gastroscopy procedure is for an endoscopic novice the intubation of the esophagus via mouth, pharynx/hypopharynx, and upper esophageal sphincter. This is not adequately simulated with the tube-like passage in the computer simulator. Concerning the risk of complications, however, intubation of the esophagus is the rather risky and unpleasant part for the patient. Furthermore, the passage of the pylorus and retroflexion are not ideally simulated, and neither are loop formations in the colon, pronounced kinks, or a very mobile sigma as mentioned by the authors. The effect on real endoscopy, especially in colonoscopy, is uncertain. Over-confidence in the computer-trained beginner could potentially result in an increased perforation rate, and therefore increased surveillance may be needed during the adaptation phase. The number of procedures required to attain basic competence in clinical endoscopy seems to be between 100 and 200 procedures for gastroscopy and colonoscopy [5]. It is hoped that ongoing studies will soon show whether simulator training results in a reduction of this clinical number [6].

References

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