Introduction
Esophagogastroduodenoscopy (EGD) is one of the commonest procedures that a gastroenterologist performs. This chapter covers how to perform a diagnostic upper endoscopy. Therapeutic interventions in upper endoscopy are discussed in Chapter 7 .
1
Upper gastrointestinal anatomy
1.1
The esophagus
The cervical segment of the esophagus begins at the upper esophageal sphincter, which is 15 cm from the incisors and is 6 mm long ( Fig. 1 ). The thoracic segment of the esophagus is approximately 19 cm long. Its lumen is open during inspiration and closed during expiration. The imprint of the arch of the aorta is sometimes apparent at 25 cm from the incisors on the left. How to describe where a lesion is in terms of anterior, posterior, right, left, is very important and is shown in Figure 2 . The transition between the esophagus and gastric epithelium (Z line) is identified by the change in color of the mucosa from pale-pink to reddish-pink.
1.2
The stomach
The stomach extends from the cardia to the pylorus ( Fig. 3 ). The fundus is the portion of the stomach above the horizontal line that passes through the cardia and that is visible in a retroflexed endoscopic view. The body is the remainder of the upper part of the stomach and is delimited at its lower edge by the line that passes through the angular notch. Endoscopically, the transition from the body to the antrum is seen as a transition from rugae to flat mucosa ( Fig. 4 ). The pylorus is a circular orifice, which leads to the first part of the duodenum.
Clinical Tip Always consider linitis plastica if the stomach fails to distend normally.
When the patient is in the lateral left decubitus position, the greater curvature is at the bottom, the lesser curvature at the top, the posterior stomach wall on the right, and the anterior stomach wall is on the left ( Fig. 4 ). The anterior wall can be visualized with transillumination, a technique used for PEG insertion (see Ch. 4 ). A normal stomach distends fully with insufflation, with the rugae flattening out ( Fig. 5 ).
1.3
The duodenum
The duodenum extends from the pylorus to the duodeno-jejunal angle. The duodenal bulb extends from the pylorus to the genu superius. The second portion (D2) extends from the genu superius to the genu inferius. The ampulla of Vater is usually found in a horizontal fold in the middle of the second portion of the duodenum ( Fig. 6 ). The accessory papilla is a small protuberance, which is usually found just superior and proximal to the ampulla of Vater.
1.4
Postoperative endoscopy of the stomach and duodenum
Common post-surgical anatomy includes a Billroth I ( Fig. 7 ), where only one lumen is present. In a Polya or Billroth II ( Fig. 7 ), two gastrojejunal orifices are visible. The afferent limb leads to the duodenum, while the efferent limb leads to the colon.
Clinical Tip The afferent limb is usually the more difficult limb to enter.
2
Indications
- •
Dyspepsia associated with alarm symptoms at any age.
- •
New onset dyspepsia in a patient ≥50.
- •
Dysphagia or odynophagia.
- •
Symptoms of GERD that persist or recur despite appropriate therapy.
- •
Persistent vomiting of unknown cause.
- •
Diseases in which the presence of upper GI pathology may affect planned management, e.g. decision to anticoagulate.
- •
Confirmation of radiological abnormalities.
- •
Suspected neoplasia.
- •
Assessment and treatment of GI bleeding (acute or chronic).
- •
Sampling of tissue or fluid.
- •
To document or treat esophageal varices.
- •
Surveillance for malignancy in high risk groups, e.g. Barrett’s esophagus, hereditary gastric cancer families.
- •
Follow-up of gastric ulcer.
- •
Follow-up of patients who undergo endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) of an early cancer.
- •
Symptoms felt to be functional in origin.
- •
‘Simple’ dyspepsia <50 years of age.
- •
Metastatic adenocarcinoma of unknown primary site when the results will not alter management.
- •
Radiographic findings of an asymptomatic/uncomplicated sliding hiatal hernia, uncomplicated duodenal ulcer or deformed duodenal bulb when symptoms are absent or respond to ulcer therapy.
- •
Surveillance of healed benign disease.
- •
Surveillance during repeated dilations of benign strictures unless there is a change in status.
Upper endoscopy (EGD) is indicated for investigation of the following presentations or for screening for pre-malignant lesions.
2.1
Dyspepsia
Age ≥50 with new onset dyspepsia:
- •
Should undergo EGD regardless of whether they have alarm symptoms.
Age <50 with dyspepsia:
- •
Patients with alarm symptoms should undergo EGD
- •
Those without alarm symptoms should undergo an initial test-and-treat approach for H. pylori
- •
Patients who are H. pylori -negative should be offered a short trial of PPI therapy
- •
Patients who do not respond to empiric PPI therapy or have recurrent symptoms after an adequate trial should undergo endoscopy.
Clinical Tips 2.2
Dysphagia or odynophagia
Unless there is a clear history pointing to a neurological cause or ENT origin for dysphagia, all patients should undergo urgent EGD as their first investigation ( Fig. 8 ). Note, patients with GERD can present with atypical symptoms including laryngitis, chronic cough or bronchospasm.
2.3
Gastroesophageal reflux
- •
Gastroesophageal reflux (GERD) can be diagnosed on the basis of typical symptoms without the need for EGD
- •
In patients with uncomplicated GERD an initial trial of empiric medical therapy is appropriate
- •
EGD should be performed if patients have alarm symptoms or symptoms suggesting complicated GERD or in patients who fail to respond to empiric medical therapy.
2.4
Persistent vomiting
EGD is indicated for isolated vomiting persisting for over 48 hours after acute intestinal obstruction and non-digestive causes have been excluded.
2.5
Assessment and treatment of upper gastrointestinal bleeding
- •
EGD is indicated in patients suspected of having an acute upper gastrointestinal bleed (hematemesis or melena) (see Ch. 7 for how to treat upper GI bleeding.)
- •
EGD should be repeated if bleeding persists when an initial examination including upper endoscopy and colonoscopy has been inconclusive ( Fig. 9 ).
Figure 9
Bleeding lesions. (A) Gastric Antral Vascular Ectasia (GAVE); (B) portal hypertensive gastropathy; (C) duodenal ulcer; (D) gastric arterio-venous malformation (AVM); (E) ulcer with adherent clot in the duodenum; (F) large benign necrotic gastric ulcer.
2.6
Investigation of chronic anemia and/or iron deficiency
- •
All patients should be screened for celiac disease ( Fig. 10f )
Figure 10
Miscellaneous. (A) Hypertrophic gastric folds in Zollinger–Ellison syndrome. (B) Anisakis worm (arrow). (C) Pyloric duplication. (D) Eosinophilic esophagitis with classic ridges. Beware dilating strictures in these patients as there is an increased risk of perforation. (E) Esophageal mucosal tear in a patient with eosinophilic esophagitis. (F) Celiac disease with scalloping of the edges of the mucosa.
- •
EGD and colonoscopy should be considered in all male patients, unless there is a history of overt non-GI blood loss
- •
EGD and colonoscopy should be considered for female patients who are post-menopausal, ≥50 years of age, or have a strong family history of colorectal cancer
- •
The presence of esophagitis, erosions or peptic ulcer disease should not be accepted as the cause of anemia until colonoscopy is performed and is normal.
2.7
When to obtain duodenal biopsies
Duodenal biopsies during upper endoscopy are indicated in the following situations:
- •
Iron-deficiency anemia with no identified cause
- •
Folate deficiency (combined with gastric biopsies)
- •
Other nutritional deficiencies
- •
Isolated chronic diarrhea
- •
Dermatitis herpetiformis
- •
Confirmation of celiac disease in patients with positive serology
- •
If parasitic diseases are suspected when a parasitological stool examination has been negative (giardiasis, strongyloidosis).
Clinical Tip The optimum number of duodenal biopsies for accurate diagnosis of celiac disease is four.
2.8
To assess portal hypertension
- •
To detect esophagogastric varices in patients with cirrhosis or non-cirrhotic portal hypertension ( Figs 9A,B, Figure 11 ) (see Ch. 7.8 for information on grading and treatment of varices )
Figure 11
Esophageal and gastric varices. (A) Small esophageal varices. (B) This image is taken in retroflexion, where multiple gastric varices are present with an erosion over one (arrow).
- •
Repeat EGD every 2 years in patients with cirrhosis in whom initial upper endoscopy showed no varices
- •
After endoscopic treatment of esophageal varices to confirm their eradication (see Ch. 7.8 for schedule for follow up of patients with varices ).
2.9
Screening or surveillance in patients at risk of upper GI malignancy
Upper endoscopy is also indicated for screening pre-malignant lesions.
2.9.1
Gastroduodenal ulcers
- •
Multiple biopsies should be performed routinely in patients with gastric ulcer with endoscopic and histological follow-up after 4–6 weeks of antisecretory treatment.
- •
Follow-up upper endoscopy is not indicated in an asymptomatic patient after treatment of a duodenal ulcer.
- •
Patients who undergo resection of an early cancer with endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) should have close follow-up.
Clinical Tip All patients with a gastric ulcer should undergo repeat EGD after 4–6 weeks of antisecretory therapy to ensure ulcer healing and for biopsies if healing is incomplete.
2.9.2
Achalasia
- •
These patients are at increased risk of developing squamous cell cancer
- •
It is reasonable to commence surveillance 15 years after symptoms began. Subsequent surveillance intervals are not clear but every 2–3 years is reasonable.
2.9.3
Caustic injury
- •
Increased risk of squamous carcinoma, especially after lye ingestion.
- •
Have a low threshold to investigate dysphagia with endoscopy.
- •
Begin surveillance 15–20 years after caustic injury.
- •
Repeat EGD every 1–3 years.
2.9.4
Tylosis
- •
There are two types of tylosis:
- ▪
Type A tylosis presents between the ages of 5 and 15 years and is associated with increased risk of esophageal cancer.
- ▪
Type B tylosis is associated with onset by age 1 and is not associated with increased risk of esophageal cancer.
- ▪
- •
Begin surveillance at age 30.
- •
Repeat EGD every 1–3 years.
2.10
Patients with a history of squamous cancer of the head, neck, pharynx, lung or esophagus
There are insufficient data to support screening; however, some authors advocate a single endoscopy with Lugol’s iodine chromoendoscopy to look for squamous esophageal cancer.
2.11
Gastric epithelial polyps
- •
All gastric polyps should be biopsied to determine whether they are hyperplastic or adenomatous ( Fig. 12 )
Figure 12
Polyps. (A) and (B) Fundic gland polyps. (C) Adenomas of the duodenum.
- •
Adenomatous polyps are at risk of malignant transformation and should be resected
- •
Surveillance endoscopy should be performed 1 year after removing an adenomatous gastric polyp. If surveillance is negative, EGD should be repeated at 3–5 years. Surveillance in patients with high-grade dysplasia or early gastric cancer should be individualized.
2.12
Gastric intestinal metaplasia
- •
Is associated with >10 fold increased risk of gastric cancer in high risk parts of the world and in patients infected with H. pylori
- •
In Western countries, endoscopic surveillance is not uniformly recommended
- •
If surveillance is performed, a topographic mapping of the entire stomach is necessary
- •
Patients with high-grade dysplasia are at significant risk for progressing to cancer and should be considered for either endoscopic resection or gastrectomy. Following endoscopic therapy, these patients (with high-grade dysplasia or cancer on histology) require close follow-up a minimum of every 6 months to 1 year.
2.13
Pernicious anemia
- •
There may be an increased risk of gastric cancer or gastric carcinoid
- •
A single EGD should be performed to identify gastric cancer or carcinoid tumor in patients with pernicious anemia
- •
Surveillance of carcinoid tumors is controversial and should be individualized.
2.14
Gastric/bariatric surgery patient
2.14.1
Pre-surgery
An EGD should be performed in all patients with upper GI tract symptoms who are to undergo bariatric surgery.
- •
An EGD should be considered in all patients who are going to undergo a Roux-en-Y gastric bypass regardless of the presence of symptoms
- •
An EGD should be considered in patients who are undergoing gastric banding to exclude large hernias ( Fig. 13A ), which could alter the surgical approach
