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Most trainees should be secure with the basic motor skills relatively quickly (roughly the first 30–50 colonoscopies). After that, the long process of mastering the intermediate skills becomes the next hurdle toward competence. These skills of navigating acute turns and managing loops are the most difficult skills for trainees to acquire. The nuances of these skills require a heightened awareness and understanding between what the eyes are seeing and what the right hand is feeling in respect to the degree of resistance, effectiveness of torquing, and fixation of the colon. It is also often difficult for staff to know how to advise on the management a specific difficult turn or loop without taking the scope personally to get a sense of how things “feel.” This makes teaching these skills difficult. More often than not, staff will simply take over the scope and advance the scope past the area of difficulty and then return the scope to the trainee with little explanation of exactly how this was accomplished. In order for fellows to grasp these nuances, a keen understanding of what is going on three‐dimensionally with the scope and loops of colon are key. Multimedia video can be of utility so that conceptually trainees can understand in general how loops develop, how different maneuvers can be used to open up turns, and how force vectors can be affected by these different techniques. Simulation can also help trainees practice some of these techniques and begin to get a sense of how these situations “feel.” Ex vivo models come close to mimicking the elasticity and feel of live tissue; however, nothing thus far can completely replace actual practice during live endoscopy [36]. For advanced endoscopic motor skills such as hemostasis techniques, training with ex vivo models have been shown to translate to improved patient‐based hemostasis skills and improved outcomes [37]. More will be discussed on this elsewhere in this text.

A less common but much more effective teaching device is the use of an external scope locating device such as ScopeGuide^® (Olympus, Center Valley, PA) [38]. This device can create real‐time visual image of how the scope is looped or positioned in an actual human colon during live cases. It does so by using a magnetic field to passively detect special markers along the length of a scope (or along a special cable in a regular scope's biopsy channel). The real‐time images allow the fellow to correlate what is being felt and seen with what is actually happening inside the patient. It can also show the effectiveness of reduction maneuvers. Despite the usefulness of such a device, these are rarely used due to cost, availability in the United States, and limited awareness of such tools. Instead, most trainees gain a sense of what is occurring inside the patient simply with greater and greater volumes of experience during patient training.

Assessment of these motor skills can be achieved by a number of means. Spot checks of these skills can be accomplished using ex vivo simulation models where a set of tasks need to be performed satisfactorily and are graded in a standardized method. These types of exams are referred to as objective structured clinical examinations (OSCE) and are frequently used in surgical training [39–41]. The ideal model for this would be a bovine ex vivo colon model (Figure 6.34) (Videos 6.11 and 6.12) . This model has been validated as a tool for assessment of competence in intermediate colonoscopy skills [34]. It has some distinct advantages over computer simulation in that the anatomy can be made as easy or difficult as desired based on the skill level of the user. Additionally, real endoscopes and therapeutic devices are used as opposed to the simulated tools used with computer simulators. This advantage can also be a major disadvantage, as the need for endoscopy equipment and laboratory space dedicated to animal training are not available at most institutions. Two alternative options to setting up a dedicated laboratory would be to utilize regional training centers such as the ASGE's animal laboratories or to bring in a group that will set up a temporary ex vivo training laboratory. Regardless of the method used, OSCE exams in general are costly from the respect of time to set up and personnel to precept exams. As such, OSCEs are best used as a summative type of exam (for a grade or for some form of certifying exam). For most centers, however, the assessment of these intermediate motor skills will still simply take place in the endoscopy suites during clinical cases. It should be stressed that this bedside assessment should incorporate objective measures that are recorded using a form such as the standardized assessment tool as discussed below. This assessment method is cheap, efficient, and can provide continuous monitoring of both cognitive and motor skills during fellows' progress through training. This can be performed with every procedure, which provides the most accurate assessment of a trainee's progress or on a periodic basis such as monthly or alternatively during every 25th or 50th colonoscopy.

Figure 6.34 An endoscopist practices on an ex vivo bovine colon model.

For terminal ileum intubation skills, there really is no substitute for patient‐based experience. Computer and ex vivo animal models do not recreate the valve adequately to be effective either for learning or for assessing this skill. Instead, practice of valve intubation with every colonoscopy should be encouraged during training. This allows the required repetition needed both to gain this skill as well as to allow programs to accurately assess and monitor ileal intubation rates in an ongoing manner.