High yield indications:

acute upper GI bleeding, to establish the exact location of hemorrhage prior to endoscopic cautery, surgery, etc

dysphagia, especially if esophageal strictures or ulcerations are seen on a previous upper GI series. Note that EGD may still be indicated if the barium swallow is normal but clinical suspicion of esophageal disease remains high

dyspepsia, if refractory to standard medical antireflux therapy. EGD is also indicated whenever a surgical antireflux procedure is planned

odynophagia, when inflammation or infection is clinically suspected, especially if esophagitis from Candida, cytomegalovirus, or herpes simplex virus is likely

surveillance endoscopy for known premalignant conditions, such as Barrett's esophagus, lye-induced strictures, Plummer-Vinson syndrome

abnormalities seen on upper GI series which require visual confirmation and tissue biopsy (eg, polyps, gastric ulcers, redundant gastric folds, strictures)

suspected gastric outlet obstruction

Lower yield indications (procedure not always appropriate):

atypical chest pain

abdominal pain of unknown etiology

routine, uncomplicated cases of gastroesophageal reflux

uncomplicated cases of duodenal ulcer demonstrated by upper GI series

Therapeutic indications for EGD are numerous and include:

sclerotherapy of bleeding esophageal varices

management of upper GI bleeding using electrocautery, photocoagulation, etc

laser ablation of esophageal cancer

endoscopic placement of esophageal stints

placement of permanent feeding tubes under endoscopic guidance (PEG tubes)

dilatation of esophageal strictures

polypectomy

dissolution of bezoars

Contraindications

acute myocardial infarction

hypoxemia with respiratory distress

hypotension and shock, regardless of etiology

massive upper GI bleeding with hypotension where emergency surgery is clearly appropriate (EGD may needlessly delay surgery and visualization is often obscured by copious amounts of blood.)

uncontrolled hypertension

patient refusal

Relative contraindications (high risk situations) include:

noncorrectable coagulopathy

recent myocardial infarction (within weeks)

severe coronary artery disease

recent upper GI tract surgery where anastomotic sites may still be "fresh"

active peritonitis

subluxation or instability of the cervical spine

anterior cervical spine osteophytes

perforated viscus

Zenker's diverticulum (possibly)

Patient Preparation Technique and risks of the procedure are explained to the patient and informed consent is obtained. In some medical centers formal consultation with gastroenterology staff is mandatory before obtaining an EGD. In other institutions procedure is arranged directly with the endoscopy scheduling desk by the primary physician. EGD may be performed on either inpatients or outpatients. Customarily, inpatients are examined briefly by the endoscopist (or his representative) the day prior to EGD in order to review details of the case, write orders, and answer patient questions. It should be emphasized that patients frequently experience apprehension and fear regarding choking on the endoscope. Careful and thoughtful reassurances from the medical team may be quite effective in allaying these anxieties. Patient is kept strictly NPO for 8 hours prior to EGD. If a morning procedure is planned, patient is NPO after midnight. If EGD is scheduled for later in the afternoon, some centers allow a light breakfast that morning. Daily medications are permitted with small sips of water. Medicines which potentially interfere with visualization of the mucosa, such as antacids or CarafateŽ, should be discontinued beforehand. If a tissue biopsy is anticipated, aspirin products, and nonsteroidal agents are discontinued well in advance (at least 5 days for aspirin). If gastric outlet obstruction is clinically suspected, nasogastric suction is performed prior to EGD in order to remove retained luminal contents. This also applies to the patient with known or suspected impairment of gastric motility. For inpatients, dentures are removed and patient is transported to endoscopy suite on a cart, along with medical chart and relevant x-rays. For outpatients, arrangements for driver transportation home must be made in advance by patient, since driving is not permitted after procedure. Once patient is in the procedure room, baseline vital signs are obtained (pulse, blood pressure, etc). Intravenous sedation is routinely given, commonly diazepam (or another short-acting benzodiazepine) and meperidine several minutes prior to examination. A topical anesthetic agent such as CetacaineŽ spray (benzocaine and tetracaine hydrochloride) is often applied to the pharynx.

Aftercare Immediately postprocedure the patient is observed in the recovery area. Vital signs are usually recorded at least once, and prn in the "high risk" patient. If no complications have occurred and sedation has worn off, patient may be discharged from the testing area. A normal diet may be resumed once gag reflex has returned. Driving is not allowed due to residual sedative effects.

Complications Morbidity and mortality of upper endoscopy is relatively low, but should not be overlooked. Statistics compiled from several large clinical series suggest an incidence of adverse outcomes of 0.1% to 0.2%. Death has been reported between 0.14-0.65/1000 endoscopies. Major complications, as described by Shamir and Schuman, are as follows.³

Perforation of esophagus or stomach: Up to 0.1% of all EGDs (some large centers report no cases of perforation). The upper esophagus above the cricopharynx appears most vulnerable. Other risk factors are esophageal cancer, strictures, or cervical osteophytes.

Bleeding: Considered rare even after biopsies, at 0.3/1000 cases. In most cases, bleeding is not due to a coagulation defect, rather it results from biopsy of friable tissue.

Cardiopulmonary complications: Significant cardiac arrhythmias are distinctly unusual. If a Holter monitor is placed, transient rhythm disturbances such as sinus tachycardia, premature ventricular contractions (PVCs), premature atrial contractions (PACs), and rarely ischemic changes may be recorded in <22% of cases. Few adverse clinical outcomes have been reported.

Other complications include the following.

Pulmonary aspiration has been estimated at 0.8/1000 cases, but carries a mortality rate of 10%. Prout demonstrated that some degree of aspiration occurs in as many as 25% of cases, using iodinated oil as a marker. No cases of clinical pneumonia developed.4

Toxicity of premedications: Minor complications are fairly common but usually inconsequential. Diazepam may cause a local phlebitis and meperidine may induce transient nausea. More importantly, the patient with severe COPD or liver cirrhosis may experience respiratory depression from this combination. In one series from England, 0.67 out of 1000 EGDs were followed by respiratory arrest requiring mechanical ventilation.5

Infection: Prospective studies have shown a bacteremia rate of 3% to 8% (positive blood cultures). Some centers routinely use antibiotic prophylaxis in patients with valvular heart disease, although the risk of endocarditis is probably extremely low.6

Miscellaneous: Parotid swelling, abdominal pain from air insufflation, transient megacolon, transient fever with pulmonary infiltrates (following sclerotherapy of varices).

Equipment The fiberoptic endoscope has replaced the rigid endoscope as the instrument of choice. This device has a length of approximately 1200 mm and diameter of 9.5-12.5 mm. The instrument shaft is composed of numerous specialized glass fibers (>30,000) which allow the transmission of light down the length of each thin fiber with minimal distortion. The multiple fiberoptic images are integrated at the proximal eyepiece unit, by means of a complex system of lenses. The endoscopist thus views a reconstructed, mosaic image at the proximal eyepiece (similar to a television image). Also within the instrument shaft are several separate channels designed for passage of optional devices such as biopsy forceps, polyp snare, cytology brush, cautery or laser device, and suction. Air may also be introduced for insufflation of the stomach. For clearing of debris from the viewing area, a jet stream of water from a separate reservoir can be flushed through one channel. At the head or handle of the endoscope are two control devices ("wheels") which maneuver the instrument tip as it is advanced, an up-down angle wheel (deflection of almost 180°) and a right-left angle wheel (deflection of 100°). The instrument head is connected with a separate cold light source (usually a halogen lamp) by means of a cable comprised of incoherent fiberoptic bundles (the "umbilical cord"). The water feed tank and automatic suction box also attach to this cable. Optional accessories include an additional eyepiece for simultaneous viewing by a second operator (the "teaching head"), an ultrasound probe for real time imaging of the stomach wall, pancreas, etc, and photographic or videotape recording devices.

Technique Performed only by an experienced gastroenterologist in a properly equipped endoscopy suite. At times, it may be necessary to carry out this procedure in an emergency room or ICU bed. Following sedation, patient is placed in the left lateral decubitus position (although successful intubation is possible in other positions). A hollow mouthpiece is inserted to protect the patient's teeth and facilitate instrument passage. The endoscope is slowly advanced orally and is "swallowed" by the patient. Once past the cricopharyngeal region the instrument is guided only under direct visualization. An important landmark is the Z-line at the gastroesophageal junction, approximately 40 cm from the teeth. The tip is then advanced into the cardia, with gentle insufflation of air. The various portions of the stomach are inspected - cardia, fundus, greater and lesser curvature, antrum. Following thus, the tip is then passed through the pylorus, into the duodenal bulb, and sometimes as far as the descending portion of the duodenum. Mucosal surfaces are reinspected as the instrument is withdrawn. Biopsies, cytologic brushings, polypectomy, cauterization of bleeding lesions, etc, are performed as indicated. Sclerotherapy of esophageal varices is not considered part of the routine EGD. This is a separate therapeutic procedure requiring additional equipment and somewhat more involved patient preparation.

Specimen All biopsy specimens and cytologic brushings are sent to the Pathology Laboratory without delay in appropriate containers and fixatives. Tissue for Gram's stain, KOH prep, and culture should be sent in sterile containers without fixative to the Microbiology Laboratory. The details of proper specimen collection, fixation, and transportation are usually supervised by the gastroenterology team.

Turnaround Time Final report on biopsy specimen histopathology is given within 2-3 days. Gram's stain and KOH prep are known immediately (within minutes if necessary) but culture results may require several days (or more than 1 week if viral culture requested).

Normal Findings No upper GI tract pathology encountered. Preliminary written report on endoscopic findings is completed immediately by gastroenterology staff and placed in medical chart before the patient is discharged from the endoscopy suite. A final typewritten report is added to the chart in 5-7 days. In general, the endoscopist comments in detail on all findings, normal and abnormal, and concludes with an overall clinical impression.

Critical Values No grading schemes or numerical "cutoffs" per se. Subjective interpretation of visual findings by an experienced gastroenterologist constitutes the data base. Important aspects of the endoscopic examination frequently commented upon include:

location of the Z-line

presence or absence of hiatal hernia

appearance of mucosal surfaces, with attention to ulcerations, erosions, strictures, masses, streaks, polyps, Barrett's-type epithelium, redundant tissue, etc

location and appearance of bleeding site(s) or varices

abnormalities in tone (spasm) of the lower esophageal sphincter or pylorus

miscellaneous abnormalities

operative procedure(s) performed during endoscopy

complications

technical adequacy of the study

In some centers, instant photographs of suspicious lesions are taken during endoscopy and included in the medical chart. In our institution, many endoscopic examinations are recorded on real time videotape for later review by the referring physician and endoscopist.

Limitations Quality of study and its interpretation are highly dependent on the expertise of the endoscopist. Recognition of subtle abnormalities and visualization of all portions of the upper GI tract require a high degree of clinical competence. A variety of technical factors may lead to a suboptimal study. Endoscopists refer to "blind spots" - regions difficult to visualize in most cases - which include the superior aspect of the duodenal bulb, portions of the fundus, and the lesser curvature below the incisura. Active uncontrolled bleeding, retained blood in the stomach, and retained food or antacids may also lead to an inadequate study. EGD should not be used for the diagnosis of esophageal motility disorders. The procedure of choice for this entity is esophageal manometry. Similarly, EGD is not a first-line test for the diagnosis of reflux esophagitis (although characteristic histologic changes may be found on mucosal biopsy).

Footnotes

References