Esophagogastroduodenoscopy
Definition, Purpose, Precautions, Description, Preparation, Aftercare, Risks
An endoscope as used in the field of gastroenterology (the medical study of the stomach and intestines) is a thin, flexible tube that uses a lens or miniature camera to view various areas of the gastrointestinal tract. When the procedure is limited to the examination of the inside of the gastrointestinal tract's upper portion, it is called upper endoscopy or esphagogastroduodenoscopy (EGD). With the endoscope, the esophagus (swallowing tube), stomach, and duodenum (first portion of the small intestine) can be easily examined, and abnormalities frequently treated. Patients are usually sedated during the exam.
Purpose
EGD is performed to evaluate or treat symptoms relating to the upper gastrointestinal tract, such as:
- upper abdominal or chest pain
- nausea or vomiting
- difficulty swallowing (dysphagia)
- bleeding from the upper intestinal tract
- anemia (low blood count). EGD can be used to treat certain conditions, such as an area of narrowing or bleeding in the upper gastrointestinal tract
Upper endoscopy is more accurate than x rays for detecting inflammation, ulcers, or tumors. It is used to diagnose early cancer and can frequently determine whether a growth is benign (not cancerous) or malignant (cancerous).
Biopsies (small tissue samples) of inflamed or "suspicious" areas can be obtained and examined by a pathologist. Cell scrapings can also be taken by the introduction of a small brush; this helps in the diagnosis of cancer or infections.
When treating conditions in the upper gastrointestinal tract, small instruments are passed through the endoscope that can stretch narrowed areas (strictures), or remove swallowed objects (such as coins or pins). In addition, bleeding from ulcers or vessels can be treated by a number of endoscopic techniques.
Recent studies have shown the usefulness of endoscopic removal of early tumors of the esophagus or stomach. This is done either with injection of certain materials (like alcohol), or with the use of instruments (like lasers) that burn the tumor. Other techniques combining medications and lasers also show promise.
Precautions
Patients should inquire as to the doctor's expertise with these procedures, especially when therapy is the main goal. The doctor should be informed of any allergies, medication use, and medical problems.
Description
First, a "topical" (local) medication to numb the gag reflex is given either by spray or is gargled. Patients are usually sedated for the procedure (though not always) by injection of medications into a vein. The endoscopist then has the patient swallow the scope, which is passed through the upper gastrointestinal tract. The lens or camera at the end of the instrument allows the endoscopist to examine each portion of the upper gastrointestinal tract; photos can be taken for reference. Air is pumped in through the instrument to allow proper observation. Biopsies and other procedures can be performed without any significant discomfort.
Esophagogastroduodenoscopy (EGD) is performed to evaluate or treat symptoms relating to the upper gastrointestinal tract. By inserting an endoscope into the mouth and guiding it through the gastrointestinal tract, the esophagus, stomach, and duodenum can be examined and abnormalities treated. (Illustration by
Preparation
The upper intestinal tract must be empty for the procedure, so it is necessary NOT to eat or drink for at least 6–12 hours before the exam. Patients need to inquire about taking their medications before the procedure.
Aftercare
Someone should be available to take the person home after the procedure and stay with them for a while; patients will not be able to drive themselves due to sedation. Pain or any other unusual symptoms should be reported immediately.
It is important to recognize early signs of any possible complication. The doctor should be notified if the patient has fever, trouble swallowing, or increasing throat, chest, or abdominal pain.
Risks
EGD is safe and well tolerated; however, complications can occur as with any procedure. These are most often due to medications used during the procedure, or are related to endoscopic therapy. The overall complication rate of EGD is less than 2%, and many of these complications are minor (such as inflammation of the vein through which medication is given). However, serious ones can and do occur, and almost half of them are related to the heart or lungs. Bleeding or perforations (holes in the gastrointestinal tract) are also reported, especially when tumors or narrowed areas are treated or biopsied. Infections have also been rarely transmitted; improved cleaning techniques should be able to prevent them.
Resources
BOOKS
Young, Harvey S., and Keeffe, Emmet B. "Complications of Gastrointestinal Endoscopy." In Sleisenger & Fordtran's Gastrointestinal and Liver Disease, ed. Mark Feldman, et al. Philadelphia: W. B. Saunders Co., 1997.
PERIODICALS
Chan, Mary F. "Complications of Upper Gastrointestinal Endoscopy." Gastrointestinal Endoscopy Clinics of North America 6, no. 2 (Apr. 1996): 287-303.
OTHER
"Understanding Upper Endoscopy." American Society for Gastrointestinal Endoscopy. <http://www.asge.org>.
David Kaminstein, MD
Additional topics
- Evoked Potential Studies - Definition, Purpose, Precautions, Description, Preparation, Aftercare, Normal results, Abnormal results
- Esophageal Pouches - Definition, Description, Causes and symptoms, Diagnosis, Treatment, Prognosis
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