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The future of simulators in GI endoscopy: An unlikely possibility or a virtual reality?

2002; Elsevier BV; Volume: 55; Issue: 4 Linguagem: Inglês

10.1067/mge.2002.120321

1097-6779

Lauren B. Gerson, Jacques Van Dam,

Gastrointestinal Tumor Research and Treatment

The inherent weaknesses of the teaching of proctosigmoidoscopy are threefold: the unhappy patient, the unhappy student, and the unhappy instructor. Let us turn our attention to the plight of the unhappy instructor. His first formidable task is to defend the patient's bowel from perforation. He must parry each determined thrust of the untrained novitiate. Moreover, he must perform the Herculean task of providing adequate endoscopic teaching material for each student to study.1Markman HD A new system for teaching proctosigmoidoscopic morphology.Am J Gastroenterol. 1969; 52: 65-69PubMed Google ScholarDavid Markman, MD American Journal of Gastroenterology, 1969 Recent advances in biotechnology have paralleled an interest in medical simulation as a method of training in GI endoscopy. One of the reported prime motivations for the development of endoscopic simulators has been that trainees in GI endoscopy are most prone to procedure-related errors during the learning process. This is also true for patient care provided by medical and surgical residents in both the inpatient and outpatient settings. How significant are these errors with regard to patient outcomes? Recent estimates describe 44,000-98,000 deaths per year in the United States caused by medical errors alone,2Kohn LT Corrigan JM Donaldson MS To err is human: building a safer health system. : National Academy Press, Washington, DC1999Google Scholar exceeding the number of deaths from highway accidents, breast cancer, and the acquired immune deficiency syndrome. Although these estimates have recently been challenged with the finding that a majority of the medical errors occur in patients who are critically ill and unlikely to leave the hospital regardless of their medical care,3Hayward RA Hofer TP Estimating hospital deaths due to medical errors: preventability is in the eye of the reviewer.JAMA. 2001; 286: 415-420Crossref PubMed Scopus (481) Google Scholar health care providers must strive to reduce the errors that occur during the delivery of routine and specialized health care. Another reason for the recent interest in medical simulation as a teaching tool is the increased demand placed on clinicians in academic medical centers, who are responsible for the majority of endoscopic training. This increased demand on physician time has led to decreased time for teaching. Theoretically, the use of endoscopic simulators should reduce the number of attending-supervised procedures performed on patients required to achieve procedural competence and also reduce the negative financial impact of training in endoscopy.4McCashland T Brand R Lyden E de Garmo P The time and financial impact of training fellows in endoscopy.Am J Gastroenterol. 2000; 95: 3129-3132Crossref PubMed Google Scholar Although endoscopic simulators might aid as adjuncts to training in academic centers, they could also create training opportunities in underserved areas not associated with academic medical centers or endoscopic training programs. And finally, because endoscopic procedures performed by trainees take longer to complete than those performed by experienced practitioners,5Jackson JL Osgard E Fincher RK Resident participation in flexible sigmoidoscopy does not affect patient satisfaction.Am J Gastroenterol. 2000; 95: 1563-1566Crossref PubMed Google Scholar the use of simulators may spare “unhappy patients” the prolonged procedural time and inherent discomfort associated with trainee-performed procedures. The current and most common method of teaching endoscopic skills, both cognitive and technical, is under the supervision of an experienced endoscopist while examining a patient. This method is similar to that of an apprenticeship.6Hochberger J Maiss J Magdeburg B Cohen J Hahn EG Training simulators and education in gastrointestinal endoscopy: current status and perspectives in 2001.Endoscopy. 2001; 33: 541-549Crossref PubMed Scopus (82) Google Scholar However, quantitative assessment of skill remains an elusive goal. Evaluation of procedural competence may be easy at the extremes, that is, the exceptionally talented and skilled trainee at one end of the spectrum, and the trainee who just cannot seem to complete an examination without the attending reaching for the endoscope to spare the patient unwarranted discomfort at the other. However, procedural competence within that spectrum of proficiency may be quite varied and difficult to study. Attempts to determine procedural competence by using objective criteria such as occurrence of complications, depth of endoscope insertion, recognition of pathologic condition, duration of procedure, and patient comfort have shown that such methods can assess competence in a manner similar to that of the physician's subjective assessment.7Proctor DD Price J Dunn KA Williamson BA Fountain RJ Minhas BS Prospective evaluation of a teaching model to determine competency in performing flexible sigmoidoscopy.Am J Gastroenterol. 1998; 93: 1217-1221Crossref PubMed Scopus (13) Google Scholar The ability to instruct and then assess the performance of a series of independent technical skills is one of the basic premises of simulator training and trainee assessment. The first endoscopic simulator was a mannequin designed in the late 1960s through which a rigid sigmoidoscope could be inserted in order to gain views of the colon.1Markman HD A new system for teaching proctosigmoidoscopic morphology.Am J Gastroenterol. 1969; 52: 65-69PubMed Google Scholar The development of flexible sigmoidoscopes led to the development of rubber or latex models of the colon and upper GI tract8Heinkel VK Kimmig JM Stomach models for training in gastrocamera examination and gastroscopy.Z Gastroenterol. 1971; 9: 331-340PubMed Google Scholar, 9Heinkel VK Kimmig JM Training on models in endoscopic examination of the stomach.Z Gastroenterol. 1972; 10: 393-398PubMed Google Scholar so that endoscopists in training could familiarize themselves with GI anatomy and pathology. Shortly thereafter, animal models were developed in an attempt to train endoscopists in newly developed techniques, such as ERCP10Falkenstein DB Abrams RM Kessler RE Jones B Johnson G Zimmon DS Endoscopic retrograde cholangiopancreatography in the dog: a model for training and research.Gastrointest Endosc. 1974; 21: 25-26Abstract Full Text PDF PubMed Scopus (30) Google Scholar, 11Noar MD An established porcine model for animate training in diagnostic and therapeutic ERCP.Endoscopy. 1995; 27: 77-80Crossref PubMed Scopus (49) Google Scholar and, most recently, EUS.12Bhutani MS Hoffman BJ Hawes RH A swine model for teaching endoscopic ultrasound (EUS) imaging and intervention under EUS guidance.Endoscopy. 1998; 30: 605-609Crossref PubMed Scopus (43) Google Scholar Early models of the biliary tract were also designed by using plumbing supplies and elastic tubing.13Leung JW Chung RS Training in ERCP.Gastrointest Endosc. 1992; 38 ([letter]): 517Abstract Full Text PDF PubMed Scopus (20) Google Scholar In addition to training in diagnostic endoscopy, animal models have been used for therapeutic maneuvers, such as EUS-guided fine-needle aspiration of the pancreas, and to confirm the site of injection during “sham” EUS-guided celiac block.14Bhutani MS Aveyard M Stills Jr, HF Improved model for teaching interventional EUS.Gastrointest Endosc. 2000; 52: 400-403Abstract Full Text Full Text PDF PubMed Scopus (46) Google Scholar Although complete or partial (isolated organ) animal models offer the advantage of practice on actual tissue and the simulation of realistic hemorrhage rates, they have the disadvantage of being cumbersome for users. Additional disadvantages include the requirement for special facilities in most cases, the need for discarding the tissue after each session, and the consideration of the moral and ethical issues associated with the use of animals or animal tissue for medical training. Computer simulators offer several advantages over the traditional animal and mechanical models. By simulating reality, they are able to provide the trainee with an approximation of the “look and feel” of the patient undergoing a procedure. In addition, they can provide the trainee with an almost limitless variety of pathologic findings. Simulators offer opportunities for repetition of hand-eye coordination skills (i.e., practice). They may also be equipped with the ability to evaluate the trainee's performance, thereby identifying potential areas of weakness before the trainee attempts the procedure on an actual patient. In a recently reported pilot study with a flexible sigmoidoscopy simulator, 5 family practice residents who trained on the simulator had improved hand-eye coordination skills and faster insertion times compared with a control group of 5 residents whose performance was based on training on patients without the use of the endoscopic simulator.15Tuggy ML Virtual reality flexible sigmoidoscopy simulator training: impact on resident performance.J Am Board Fam Pract. 1998; 11: 426-433Crossref PubMed Scopus (106) Google Scholar Virtual reality computer simulation was first successfully applied to the development of flight simulators for the aviation industry and for nuclear reactor operations training. Application of this advanced technology to medical and surgical procedures was inevitable and is continuing at a rapid pace. Early pioneers in endoscopic simulator development established the required features of a training module.16Noar MID Soehendra N Endoscopy simulation training devices.Endoscopy. 1992; 24: 159-166Crossref PubMed Scopus (32) Google Scholar As an endoscope is passed through the patient surrogate, sensors relay information to the computer for image display and interaction. Variable resistance devices provide tactile feedback. Images are displayed through interactive video technology, in which images are stored on a laser disk; computer graphic simulation, in which images are computer generated; or a combination of both (video graphic tool technology). Recent advances in computer technology have enabled significant improvements in graphic display.17Noar MD Robotics interactive endoscopy simulation of ERCP/sphincterotomy and EGD.Endoscopy. 1992; 24: 539-541Crossref PubMed Scopus (31) Google Scholar, 18Tasto JL Verstreken K Brown JM Bauer JJ Preop endoscopy simulator: from bronchoscopy to ureteroscopy.Stud Health Technol Inform. 2000; 70: 344-349PubMed Google Scholar As an example, one flexible sigmoidoscopy simulator includes didactic modules and practice cases. The didactic content includes 3-dimensional videos demonstrating the anatomy and embryology of the colon; an atlas of pathologic findings, indications, contraindications, and complications associated with the procedure; and live video segments that instruct the student how to use the endoscope, including insertion and retroflexion. The 6 patient procedures that follow demonstrate a variety of pathologic findings, including colitis, hemorrhoids, diverticulosis, polyps, and cancer. Associated features, which include a virtual attending and external view, demonstrate a variety of loop formations and advise the examiner how to overcome technical difficulties. The virtual lumen expands with air insufflation and collapses with suction, and the patient will complain audibly of discomfort or even demand cessation of the examination in certain scenarios. At the end of the examination, a critique is provided that includes the time of the examination, a report on the successful recognition of pathologic condition, the degree of air insufflation and patient degree of discomfort, the percentage of mucosa visualized, and the ability to perform retroflexion. If perforation occurs, the procedure is immediately terminated. Validation studies, already in progress, have been designed to assess the role of the flexible sigmoidoscopy simulator in teaching internal medical residents how to perform the procedure. In one such study, the ability of the simulator to introduce the procedure to internal medical residents is being compared with traditional bedside teaching. Performance during 5 procedures performed on patients is compared after unlimited time on a virtual reality simulator versus training during 10 physician-assisted procedures performed on patients undergoing colorectal cancer screening (sigmoidoscopy without sedation). Medical resident performance is judged by primarily objective criteria. In addition, patients undergoing the procedure are queried with respect to their degree of comfort/discomfort for an additional study objective. In another study conducted by an internal medicine credentialing agency, the sigmoidoscopy simulator is being validated by clinicians who have performed at least 25 sigmoidoscopies. In this study, a virtual reality simulator is being assessed to determine whether it can be used as a method to credential or potentially recredential health care providers who perform the procedure. Virtual reality simulators designed to teach upper and lower endoscopy, a variety of urological procedures, and laparoscopic operations are commercially available and the preliminary results of a study with the upper endoscopy simulator have been reported.19Fregonese D Casetti T Cestari R Chilovi F D'Ambra G Delle Fave G et al.Basic endoscopy training: usefulness of a computer-based simulator.Gastrointest Endosc. 2001; 53 ([abstract]): AB81Google Scholar In this study, a cohort of 11 gastroenterology trainees without previous endoscopic experience who performed upper endoscopy after mere observation of procedures performed by the attending physician was compared with a cohort pretrained for 10 hours on an endoscopic simulator. Each fellow was requested to perform 20 upper endoscopic procedures and was allowed a maximum of 15 minutes. Although there were no significant differences between the groups with regard to mean intubation attempts, skipped lesions (defined as lesions of 5 mm or greater, or grade 2+ varices), or the mean procedure duration (12.4 minutes vs. 10.6 minutes in the simulator group), there were fewer incomplete procedures and need for assistance from the attending physician in the group trained on the simulator (p < 0.005).20Ferlitsch A Glauniner P Gupper A Schillinger M Haefner M Gangl A et al.Virtual endoscopy simulation for training of gastrointestinal endoscopy.Gastrointest Endosc. 2001; 53 ([abstract]): AB78Google Scholar In another pilot study, a group of 11 expert endoscopists (defined as having performed more than 1000 EGDs and colonoscopies) was compared with a group of 13 novices, with the novice group randomized to simulator training, 2 hours per day (n = 7) or no training (n = 6).20Ferlitsch A Glauniner P Gupper A Schillinger M Haefner M Gangl A et al.Virtual endoscopy simulation for training of gastrointestinal endoscopy.Gastrointest Endosc. 2001; 53 ([abstract]): AB78Google Scholar Groups were initially assessed with regard to two virtual upper endoscopic examinations and two virtual skill tests. After 3 weeks, the groups were reassessed with two different endoscopic cases and the same skill tests. Although the expert group was superior in the initial testing for the virtual skill tests and endoscopic skills, the second assessment no longer demonstrated differences between the expert group and the group trained on the simulator. When compared with the nonsimulator group, the endoscopists in the group trained on the simulator demonstrated significantly faster insertion time and fewer adverse events (defined as inappropriate or unsuccessful retroflexion, excessive wall pressure, or impaired luminal viewing). Because this was merely a pilot study (and limited in scope), further studies will be required comparing bedside teaching with teaching with assistance from endoscopic simulators in order to determine their role in an academic teaching setting. This brief review has left many questions unanswered and even more unasked. What it the optimal use of medical simulators? For whom were they intended? What procedures should be taught? Should nongastroenterologists be trained in GI endoscopy by using these devices? Should nonphysicians be trained in procedures other than sigmoidoscopy? Should internal medicine credentialing organizations determine who should perform or continue to perform endoscopic procedures based entirely or in part on their performance on virtual reality simulators? And finally, who should make these decisions of such profound importance to our specialty and on what criteria should they be based? As the results of validation studies currently in progress are awaited, it must be acknowledged that the initial goals of medical simulation have been achieved. When the participants of an annual course in advanced GI endoscopy were asked to evaluate an endoscopy simulator, 91% concluded that the simulator would be very or somewhat useful in their training and a majority concluded that simulation would have a potential role in the training and recertification of physicians.21Aabakken L Adamsen S Kruse A Performance of a colonoscopy simulator: experience from a hands-on endoscopy course.Endoscopy. 2000; 32: 911-913Crossref PubMed Scopus (69) Google Scholar Even greater advances in both the visual and sensory components of these devices are anticipated, which will make today's simulators appear crude and awkward by comparison. However, such technical achievements may not clarify the role of medical simulators in GI endoscopy but only serve to make their role even more difficult to define. Based on encouraging preliminary data, however, the future of simulators in GI endoscopy appears promising.