vivo animal tissue simulators: Erlanger and EASIE models
In 1996, Hochberger and Neuman created an innovative simulator using pig organs obtained from a slaughterhouse and fastened to a plastic platform [25, 26]. In order to create a model that would allow training and practice in therapeutic techniques, Hochberger then created a highly realistic simulation of pulsatile arterial bleeding (Figure 1.11a,b). This was accomplished by inserting tubes through the stomach, and sewing real arteries attached to a roller pump capable of pulsatile perfusion with a cherry‐colored saline solution. Following this, Hochberger developed representations of other pathologies for this model, including polyps, varices, and strictures [27, 28].
Currently, there are two basic model types based on these principles. The original Erlanger model features pig organs inserted into a dummy mannequin. This model has been used in the simulation of various laparoscopic surgical procedures [29]. Hochberger then created the compact‐EASIE model, a smaller portable, lightweight version using a tabletop platform. There are now several commercially available versions of this type of simulator in which only the organs needed for endoscopy simulation are secured to the platform plastic tray (Figure 1.11a,b). For example, only the esophagus to the duodenal bulb may be needed for a specific training session, but the model has the flexibility to allow the liver and hepatobiliary tree for an ERCP simulation involving fluoroscopy. Multiple therapeutic procedures may be demonstrated, taught, and evaluated on both of these animal tissue‐based simulators. With the advent of portable, compact tabletop ex vivo models that can easily be shipped to a location along with pre‐prepared frozen organ packages, some of the obstacles to simulator availability have diminished.
Figure 1.11 (a) Compact‐EASIE porcine model hemostasis simulator. (b) Close‐up view of porcine stomach with arteries sutured in attached to catheters for hook‐up to tubing connecting vessels to pump. The trainee puts together a band ligation device for varices treatment simulation.
Just as in the Lucero et al. experience described above, training sessions using the Erlanger or EASIE models are labor intensive, with high faculty‐to‐trainee ratios. Moreover, the advance work to organize and staff workshops using this technology is extensive. Since the compact EASIE is relatively portable, its use may allow easier access to animal simulator training at local sites, but this is counterbalanced by the need to have the required expertise to prepare the animal tissues and “load” the models. For this training technique to be applied widely, many expert teachers will still need to be trained; the feasibility of 1 day “train‐the‐trainer” courses has now been demonstrated [38].
On the other hand, like the static models before it, the EASIE model allows trainees to perform multiple repetitions of the same technique. The use of real tissue and the capability of performing advanced therapeutic procedures make this an attractive simulator for practitioners hoping to learn new techniques and for advanced fellows to practice and improve their skills, as well as to acquire new abilities [39].
By devising a way to allow realistic simulation of diagnostic and therapeutic techniques using a model that is portable, Hochberger set in motion a rapid expansion in the use of hands‐on training for GI fellows in the United States and Europe. Workshops at courses such as the annual NYSGE course and at national and regional endoscopy meetings proliferated. Around 2000, under the leadership of Christopher Gostout, the ASGE launched a major initiative to create opportunities for ex vivo model training in a central freestanding location. This effort culminated in the creation of the Integrated Technology and Training (ITT) center of the ASGE, and the development of a standardized first year fellows’ course curriculum, integrating a day of intensive hands‐on work in the ex vivo laboratory with interactive didactic lectures. The ongoing ASGE and industry support for these courses has led to over 300 fellows each year since 2005 attending the ITT workshop in the summer of their first year of fellowship. Through this effort, ex vivo hands‐on training to some degree has become part of the standard endoscopy training for US GI fellows. Efforts to extend such opportunities for advanced endoscopy trainees and to individuals in practice have expanded considerably since the mid 2000s and are addressed in Chapters 37 and 38 of this book.
Just as important as his role in the development and popularization of the ex vivo model, Hochberger made several other key contributions to the evolution of endoscopy training. Expanding on the course concept of Lucero, he embedded the simulator work into rigorous training programs, which deconstructed instruction according to specific targeted skill sets. Regardless of the endoscopic procedure being taught, each learning station was assigned separate specific learning objectives. Manual hand–eye skills were taught using specially designed coordination exercises. Communication skills between endoscopist and assistant were emphasized. Assessment of skills was broken down by specific procedure steps to ensure that all details received specific attention and instruction. The structure of the workshops he designed in collaboration with his German colleagues and his colleagues from the NYSGE incorporated expert demonstration of proper technique, repetitive practice with sufficient endoscope time per trainee per skill station to do so, self‐assessment, and instructor feedback. These components have remained the essential backbone of all subsequent ex vivo model‐based training. In addition, Hochberger first promoted the concept of “team training,” focusing on the importance of coordinating training among the endoscopist and assisting staff.
Live animal courses
Although clearly advantageous for the above reasons, live animal courses also present some substantial drawbacks. Among these are that animals are very expensive to maintain and there are significant ethical considerations in using animals for training. These ethical considerations are magnified by the fact that ex vivo alternatives now exist for teaching most techniques and do not require sacrificing any animals
