An endoscopic procedure to visualise the upper part of the gastrointestinal tract,. performed using a camera incorporated into a flexible tube passed through the mouth and into the throat and stomach.
Gastro-duodenoscopy/Upper GI Endoscopy (OGD) is a diagnostic endoscopic procedure that visualises the upper part of the gastrointestinal tract up to the duodenum. It is a minimally invasive procedure and does not require any significant recovery after the procedure (unless sedation has been used). However, a sore throat is common
Indications for undergoing an upper GI endoscopy include:
- Unexplained anemia (usually along with a colonoscopy)
- Upper gastrointestinal bleeding as evidenced by hematemesis or melaena
- Persistent dyspepsia in patients over the age of 45 years
- Heartburn and chronic acid reflux - this can lead to a precancerous condition called Barrett's esophagus
- Persistent vomitin
- Dysphagia - difficulty in swallowing
- Odynophagia - painful swallowing
- Surveillance of Barrett's esophagus
- Surveillance of gastric ulcer or duodenal ulcer
- Occasionally after gastric surgery
Confirmation of diagnosis/biopsy
- Abnormal barium swallow or barium meal
- Confirmation of celiac disease (via biopsy)
- Treatment (banding/sclerotherapy) of esophageal varices
- Cutting off of larger pieces of tissue with a snare device (e.g. polyps, endoscopic mucosal resection)
- Application of cautery to tissues
- Removal of foreign bodies (e.g. food) that have been ingested
- Dilating or stenting of stenosis or achalasia
- Endoscopic retrograde cholangiopancreatography (ERCP) combines OGD with fluoroscopy
- Endoscopic ultrasound (EUS) combines OGD with 5–12 MHz ultrasound imaging
The patient is told not to eat, for at least 6 hours before the procedure. Most patients are given a mild sedation although it is possible to have the procedure carried out using an analgesic throat spray. The main risks are bleeding and perforation. The risk is increased when a biopsy or other intervention is performed.
The patient lies on his/her left side with the head resting comfortably on a pillow. A mouth-guard is placed between the teeth to prevent the patient from biting on the endoscope. The endoscope is then passed over the tongue and into the oropharynx. This is the most uncomfortable stage for the patient. Quick and gentle manipulation guides the endoscope into the esophagus. The endoscope is gradually advanced down the esophagus making note of any pathology. The endoscope is passed through the stomach and through the pylorus to examine the first and second parts of the duodenum. Once this has been completed, the endoscope is withdrawn into the stomach and a more thorough examination is performed in order to examine the fundus and gastroesophageal junction. Any additional procedures are performed at this stage. The air in the stomach is aspirated before removing the endoscope. Still photographs can be taken during the procedure and later shown to the patient to help explain any findings.
In its most basic use, the endoscope is used to inspect the internal anatomy of the digestive tract. Often inspection alone is sufficient, but biopsy is a very valuable adjunct to endoscopy. Small biopsies can be made with a pincer (biopsy forceps) which is passed through the scope and allows sampling of 1 to 3 mm pieces of tissue under direct vision. The intestinal mucosa heals quickly from such biopsies.
Biopsy allows the pathologist to render an opinion following histological examination of the biopsy tissue with light microscopy and/or immunohistochemistry. Biopsied material can also be tested on urease to identify Helicobacter pylori which if found can be easily treated.