and prevention of difficulties are a major component of ensuring patient safety and comfort. This may require using a lower setting of air insufflation for instance or defining the amount of the procedure that should be performed by trainees (e.g., limiting polypectomy, sphincterotomy, or other therapeutic steps until the preliminary diagnostic skills have been mastered). This emphasizes the importance of establishing clear limits on what the trainee is expected to do during a procedure and when the trainer will take over the procedure. By doing this, the teacher will manage the emotional aspects of learning better and avoid the negative connotation of taking over a procedure. The other important components of training (covered in the Chapter 3) include the medicolegal aspects, appropriate informed consent, and so on.
Inspection
Once the scope has been advanced to the desired limit, and that location has been confirmed in some way, the next step is to carefully withdraw the scope while thoroughly examining the entire mucosal surface. This requires essentially the same skills as in scope navigation. Again, although this can be viewed as a technical component, there is no doubt that cognition plays an important role. Detection of specific lesions, such as the findings of celiac disease, eosinophilic esophagitis, and so on, is more related to an awareness of what is being looked for rather than being solely based upon technique. This is particularly relevant to endoscopic reporting, in which a thorough description of tumor characteristics and relation to landmarks may have great implications for the surgical approach for instance, and a repeat endoscopy will be required if communication between endoscopist and the surgeon is not sufficiently specific and detailed. Training in the cognitive aspects of image interpretation and assessment can be developed by didactic resources such as review of atlases and by direct mentored experience. The development of such cognitive skills should occur at the same time that the trainee learns to carefully inspect the entire mucosa, as these skills are complementary and dependent on one another.
The technical requirements of inspection differ somewhat depending on the nature of the procedure. In upper endoscopy, for example, the papilla and medial wall of the duodenum are common blind spots without careful and deliberate inspection, and may not always be easily obtained during EGD. In EUS or ERCP, the oblique viewing nature of the endoscope provides particular limitations and careful attention must be paid. In EUS imaging, the ultrasound view has very specific requirements to ensure that adequate imaging of specific structures has occurred. Depending on the indication for the procedure, repositioning of the patient, addition of fluid in the lumen, removing mucous, using chromoendoscopy, or narrow‐band imaging may be particularly useful. For enteroscopy or colonoscopy, inspection is a crucial aspect that has been highlighted by recent trials of adenoma detection. Slow withdrawal of the endoscope must be achieved, while at the same time using frequent movement of the tip of the endoscope to ensure that the entire circumference of the mucosa is inspected. Proper insufflation is helpful in effacing the mucosa, making polyps more easily identified. In several areas, repositioning of the patient may also be useful. Care must be taken to avoid rapid expulsion of the scope as this may occur when the tip of the endoscope is not anchored in place. To avoid unintended sudden changes in endoscope position, careful attention to both the endoscopic image and sensation in the right hand is necessary. Scope readvancement may be required if a region of the wall is not seen on first pass. Flexures and folds in the colon may create potential blind spots in colonoscopy for instance, or in the case of EUS, there are known blind spots in the stomach or regions that are outside of the limit of the ultrasound image. The endoscopist must always be aware of these locations and ensure that they are properly evaluated. Complete examination of specific areas within the GI tract, such as the distal rectum and anorectal junction, requires the endoscopist to be able to retroflex the endoscope in the rectum. This may also be required for complex polypectomy or other therapeutic maneuvers elsewhere in the GI tract. In the upper GI tract, for example, complete inspection of the stomach requires the endoscopist to be able to retroflex the scope to provide a complete view of the cardia and fundus. Retroflexion requires the endoscopist to understand the concept of paradoxical movement; as the retroflexed scope is withdrawn, the tip gets closer to the esophagogastric junction. Once the scope is retroflexed, the endoscopist can more accurately view the entire lesser curvature with a good view of the incisura angularis and the proximal lesser curvature. The hiatal opening can be viewed from below, and lesions in the cardia and fundus can be accurately evaluated. The combination of retroflexion, withdrawal of the scope, and rotation are required to fully evaluate the stomach.
Assessment of mucosal inspection can be done in terms of the percent of mucosal surface evaluated. This is best done using virtual reality simulators, where these metrics are readily obtained electronically. A skilled endoscopist can achieve this more efficiently than a novice, but it must be emphasized that quick endoscopy that does not provide complete mucosal inspection is a poor trade‐off. At the present time, documentation of imaging quality in lower GI procedures typically involves photo or video documentation of specific landmarks such as the terminal ileum, ileocecal valve, and appendiceal orifice. In addition, aspects such as bowel preparation and residual bodily fluids may impair visualization of subtle lesions, and trainees should be encouraged to evaluate and document their presence. In endoscopic ultrasound, training should give consideration to the evaluation and documentation of the adequacy of examination on an intent‐to‐image basis.
Instrumentation
A fundamental skill that should be in the skill set of any GI endoscopist is to be able to use instrumentation placed through the accessory channel to accomplish biopsy, snare a polyp, perform an injection, or apply energy for tissue destruction or hemostasis. Virtually, all GI endoscopes have a working channel through which instruments can be introduced. Although side‐viewing endoscopes are used in ERCP, or linear EUSs have an elevator that can be used to deflect the angle of accessories that exit the scope tip, most upper and lower endoscopes do not have a separate deflector for the instrument channel, hence control of the instrument must be achieved by orienting the working channel properly using the combination of tip deflection and torque of the scope to provide the best working angle between the instrument and the target. The endoscopist must be able to maintain a stable endoscopic position and clear view at all times when performing therapeutic procedures. At times, it may be helpful to have an assistant hold the endoscope in place while advancing the instrument, particularly if a stable position is hard to maintain.
Accurate targeting is a learned skill that can be practiced and evaluated. Metrics to evaluate targeting include time required to instrument the “lesion” once the target mucosa has been visualized, accuracy of placement of the instrument relative to the target, and number of attempts to direct the instrument to the target. This is relevant to a number of procedures such as biopsy in EGD, fine‐needle aspiration in EUS, cannulation in ERCP, and polypectomy in colonoscopy. Again, mastery of these tasks requires sufficient skill in scope handling and navigation, as well as an understanding of the cognitive aspects, such as indications for the intervention, potential complications, alternatives, and so on. This final stage of training is typically only reserved for advanced trainees who have successfully demonstrated proficiency in the fundamental earlier stages.
Simulators and task deconstruction
