Figure 5.1 White light high‐resolution endoscopy (HRE) image of (a) early erosive esophagitis (Mayo Clinic, Jacksonville, USA) and (b) Los Angeles Grade D reflux esophagitis (University of Utah Health Sciences Center, Salt Lake City, USA).
(Contributed with permission from Advanced Digestive Endoscopy: Comprehensive Atlas of High‐Resolution Endoscopy and Narrowband Imaging. Edited by J. Cohen. Blackwell Publishing. 2007: p. 177.)
In some patients, routine administration of moderate sedation may not be effective. This includes patients who consume moderate to large amounts of alcohol and who use benzodiazepines and/or narcotics. These patients should be advised that the administration of conscious sedation might not produce significant sedative effects. In such cases, utilization of propofol or general anesthesia may be required and has been shown to be associated with a higher probability of a complete examination [10].
Landmark and pathology recognition
It is important for the trainee to recognize important landmarks during an EGD and document these findings appropriately. The location of the gastroesophageal junction (GEJ) in centimeters from the endoscope insertion point should be noted. In order to characterize this landmark, trainees must be able to discern the top of the gastric folds, which can be accentuated by gentle suction or by identification of the distal end of the longitudinal palisade vessels commonly seen in normal esophageal mucosa. The appearance of the GEJ should be described as regular or irregular, and with or without findings to suggest esophagitis. A standard classification system (such as Los Angeles Classification, Figure 5.1) should be used for all examinations where erosive esophagitis is present [11].
Figure 5.2 Long‐segment BE is evident on this low‐magnification white light HRE view (University of Amsterdam, Amsterdam, Netherlands).
(Contributed with permission from Advanced Digestive Endoscopy: Comprehensive Atlas of High‐Resolution Endoscopy and Narrowband Imaging. Edited by J. Cohen. Blackwell Publishing. 2007: p. 182.)
It should also be noted if tongues or segments of salmon‐colored mucosa are present. The location of the Z‐line is required to determine the length of a segment of suspected or established BE. In the absence of BE, the Z‐line is located at the top of the gastric folds. If BE is found (Figure 5.2), the Prague classification system should be used to document the maximal and circumferential involvement of intestinal metaplasia [12]. If a hiatal hernia is present, the endoscopist should mark the proximal and distal end of the hernia sac and whether Cameron erosions are present.
Other important landmarks include the gastric body and antrum (Figure 5.3), gastric fundus and cardia during the retroflexed view (Figure 5.4), pylorus (see Figure 5.3), duodenal bulb (Figure 5.5), and first and second portions of the duodenum (Figure 5.6).
In addition to reflux esophagitis and BE, the fellow must also learn to recognize a number of commonly encountered pathological findings. These include inlet patches, esophageal candidiasis, features suggestive of eosinophilic esophagitis, rings, diverticula, esophageal varices, achalasia, hiatal hernia, fundic gland polyps, hyperplastic polyps, ulcers, gastric antral vascular ectasia (GAVE), features suggestive of H. pylori gastritis and NSAID‐associated gastropathy, atrophic gastritis, subepithelial lesions, Brunner’s gland hyperplasia, duodenal diverticula, duodenal and ampullary adenomas, findings suggestive of celiac disease, malignancy, among other findings that can occur in the upper digestive tract (Figure 5.7).
Technical aspects
The most important technical aspects for the trainee to master include successful esophageal intubation, retroflexion in the stomach, pyloric intubation, traversal of the duodenal sweep, thorough examination of the mucosa, and the ability to perform biopsies and therapeutic maneuvers such as those required for endoscopic hemostasis and removal of foreign bodies.
Figure 5.3 Low‐magnification white light HRE image of normal gastric antrum and pylorus (University of Utah Health Sciences Center, Salt Lake City, USA).
(Contributed with permission from Advanced Digestive Endoscopy: Comprehensive Atlas of High‐Resolution Endoscopy and Narrowband Imaging. Edited by J. Cohen. Blackwell Publishing. 2007: p. 215.)
Figure 5.4 Low‐magnification white light HRE image of normal fundus with two small fundic gland polyps and hiatal hernia seen in retroflexed view (Mayo Clinic, Jacksonville, USA).
(Contributed with permission from Advanced Digestive Endoscopy: Comprehensive Atlas of High‐Resolution Endoscopy and Narrowband Imaging. Edited by J. Cohen. Blackwell Publishing. 2007: p. 214.)
Equipment
The standard current video‐endoscope consists of a control section with angulation knobs, suction and air/water valves, and instrument channel port, and an insertion tube with a distal deflectable tip (Figure 5.8). A charge‐coupled device (CCD) chip allows for transmission of the image to a display monitor. The operating channel ranges in size from 2.0 mm for transnasal endoscopes to close to 4.2 mm for therapeutic endoscopes. The insertion tube diameter ranges from approximately 5.0–6.0 mm for transnasal or ultra‐slim endoscopes to 9.0–10.0 mm for diagnostic endoscopes and up to 10.0–13.0 mm for therapeutic endoscopes. The larger channels of the therapeutic endoscopes allow for more effective suctioning of blood and gastric contents as well as passage of larger accessories.