CHAPTER 75
Upper gastrointestinal endoscopy

Emmanuel Coronel¹ and Irving Waxman²

¹ University of Texas, MD Anderson Cancer Center, Houston, TX, USA

² Rush University System for Health, Chicago, IL, USA

History and background

The first endoscopic device was introduced in 1806 by Philip Bozzini, who developed a “Lichtleiter” (light conductor) “for the examinations of the canals and cavities of the human body.” However, the Vienna Medical Society disapproved of such a device, and the development stalled. A rigid endoscope was first introduced into a human in 1853. However, it was not until the mid‐20th century that Rudolf Schindler, the father of modern endoscopy, pioneered the use of gastroscopy through the use and development of a semirigid gastroscope.

The use of electric light was a significant step in the improvement of endoscopy. These lights were at first external; later, smaller bulbs became available, making internal light possible. One of the major developmental milestones for endoscopy was the invention of a superior glass fiber, which Basil Hirschowitz applied to the development of flexible endoscopes. The technology not only resulted in the first useful medical endoscope but revolutionized endoscopic uses and led to practical fiberoptics.

Video endoscopy, introduced in the mid‐1980s, has dramatically improved and expanded the field of endoscopy. The endoscopic image is generated electronically, using a charge‐coupled device (CCD) located at the tip of the endoscope, and most current video endoscopes use a color CCD that obtains the image in color on the tip of the endoscope. These devices provide 30 000 to 850 000 pixels of resolution. By incorporating high pixel‐density CCDs, high‐resolution endoscopes provide images that display vivid mucosal detail. High‐resolution endoscopes are capable of discriminating objects 10–70 μm in diameter; in comparison, the naked eye is capable of discriminating objects 125–165 μm in diameter. The video endoscope has controls for introducing air, water, and suction, as well as knobs for moving the endoscope tip up, down, and to the right and left and multiple function buttons for image and video capture.

Technical considerations

Upper GI endoscopy is a highly technical procedure that requires adequate and extensive training to be performed safely. In the United States, physicians require a documented minimum number of endoscopic procedures to be credentialed, and a minimum of 100 procedures yearly has been suggested by the British Society of Gastroenterology to maintain a high‐quality examination standard.

Endoscopy requires close cooperation between different medical professionals such as endoscopists, nurses, endoscopy technologists, pathologists, and anesthesiologists. Upper GI endoscopy should be performed in medical facilities such as ambulatory centers or hospitals that have an adequate set up for the preprocedural and postprocedural care of patients and have the appropriate space and equipment to perform this medical procedure safely.

In addition to having the appropriate space, providing high‐quality endoscopy services requires a significant investment in endoscopes, processors, accessories, devices, and a reliable high‐level disinfection and storage system to reprocess the equipment. In many tertiary care institutions, a mobile endoscopy unit is required to provide services for critically ill patients who cannot be transported to the designated endoscopy area.

Introducing the endoscope

Most small‐diameter video endoscopes can be readily passed under direct vision through the upper esophageal sphincter. The tip of the instrument is advanced in the midline in the direction of the closed cricopharyngeal sphincter. During conscious sedation, the patient is asked to swallow. Under direct vision, the tip of the instrument is passed from the epiglottis and larynx into the proximal esophagus behind the pyriform sinuses. In the past, endoscopes were passed blindly, aided by the swallowing action. The direct vision technique allows inspection of the pharynx, epiglottis, and vocal cords before insertion. Furthermore, direct imaging may decrease the risk of the inadvertent passage of the endoscope into a proximal esophageal diverticulum. Small‐diameter video endoscopes can also be passed transnasally (after the local application of lidocaine gel and a nasal decongestant) and may provide the opportunity to perform unsedated endoscopy.

The routine upper gastrointestinal endoscopic examination

The endoscopic examination of the upper GI tract begins with examination of the upper esophagus as the endoscope is passed through the upper esophageal sphincter (UES). Because the proximal esophagus is best examined on withdrawal, the endoscope is usually passed to the midesophagus, where the formal examination begins. At approximately 39 cm lies the ora serrata, also called the “Z‐line,” which is the junction between the pearly stratified squamous mucosa and the gastric columnar epithelium. The esophageal folds can be seen to change with air distension. It is possible to recognize extrinsic pressure on the esophagus from adjacent structures, such as the aorta and left mainstem bronchus. Impingement by the diaphragm is apparent in the upper stomach and defines the presence of a hiatal hernia.

With slight angulation to the left and anteriorly, the endoscope is passed into the stomach. Air is insufflated to distend the stomach. It is essential to notice the presence of food, bile, or blood in the gastric lumen. Gastric fluid in the cardia should be aspirated to improve endoscopic inspection and reduce the likelihood of regurgitation and aspiration during the procedure. The gastric mucosa should be cleaned and carefully inspected. Observations should be made about the color, texture, size of folds, and distensibility under insufflation. The gastric folds begin in the upper portion of the stomach and extend down to the entrance into the antrum. With gentle distension of the stomach, these folds often flatten. The size, number, and depth of mucosal defects are noted. Indentation of the lumen by mural lesions, or extrinsic compression by extrinsic organs, can be observed.

A complete examination of the stomach requires a retroflexed view. The maneuver takes place in the antrum with a 180° flexion of the endoscope in a distended stomach. This view can be achieved by turning the up/down knob completely backwards and rotating the endoscope to the left and right. The gastroesophageal (GE) junction, cardia, and fundus can be examined by pulling the endoscope. Retroflexion also permits inspection of a hiatal hernia. Lesions in a hiatal hernia and the GE junction are best viewed in a retroflexed position. The antrum of the stomach is marked by the incisura, a fold on the lesser curve of the stomach. The antrum can be easily identified by the lack of folds and a conical shape. The antrum is the site of the initiation of peristalsis and terminates in the pylorus. Vigorous contractions begin in the proximal antrum and progress through the antrum at a frequency of approximately three per minute. Peristalsis may be weak or absent in heavily sedated patients or those with severe gastroparesis. In any case, quantification of peristalsis may not be possible and is not practical.

Once the examination of the body and antrum has been completed, the endoscope is advanced to the pylorus. It is sometimes necessary to create a loop along the greater curvature before the tip of the endoscope can progress through the pylorus. Detailed inspection of the duodenal bulb is possible by using subtle wrist movements and the right/left knob, also called the “small dial.” The endoscope is then passed beyond the apex of the bulb into the second descending portion of the duodenum. The passage from the bulb into the descending duodenum is readily performed with a turn of the endoscope to the right and turning the up/down knob, also called the “large dial,” backwards. The duodenal bulb is usually free of folds; duodenal Kerckring folds begin in the descending portion of the duodenum. A tangential view of the ampulla is usually appreciated, while examination of the ampulla is difficult with a standard upper endoscope and is usually performed with a duodenoscope, a transparent cap attached to the forward view endoscope, which allows for a detailed examination as well.

After completion of the examination in the duodenum, the endoscope is withdrawn, during which time the endoscopist can examine the mucosa of the duodenum, stomach, and esophagus. If there is any suspicion of a lesion in the stomach, it is essential to inflate the stomach, flattening the folds and allowing a detailed examination of the gastric mucosa for small ulcers, angioectasias, and early gastric cancer. After completion of the examination of the stomach, air, or CO₂ should be aspirated. During withdrawal of the endoscope through the esophagus, it is crucial to examine the upper esophagus, the UES, and the larynx because these may not have been examined in detail during the initial introduction.

Attention must be paid to all quality indicators of endoscopy, and reporting should be accurate and complete. This chapter demonstrates normal and pathological endoscopic findings in the esophagus, stomach, and duodenum (Figures 75.1–75.99).