A Gastroscopy is a form of endoscopic investigation.
It is essentially a ‘camera test’ whereby the oesophagus, stomach and duodenum (first part of the small intestine) is directly visualised using a flexible scope (‘camera’) that is inserted through the mouth. Through the scope, a small forceps or a snare can be introduced to allow biopsies and removal of polyps.
A Gastroscopy can be performed for suspicion of either a benign or malignant condition.
The common benign conditions that warrant a gastroscopy include Gastritis, Gastric/Duodenal ulcer, Helicobacter.pylori, Gastric acid reflux disease and Gallstones.
The common symptoms associated with the above benign conditions include pain or discomfort or bloating at the upper abdomen, burning sensation in the middle of the chest (heartburn) and the passage of black stools or fresh blood.
The common malignant conditions that warrant a gastroscopy include Gastric cancer and Oesophageal cancer.
The common symptoms associated with the above malignant conditions include severe upper abdominal pain, poor appetite with a full sensation after a small meal, obvious abdominal swelling/distension, swallowing difficulties with food getting stuck and massive weight loss.
A Gastroscopy is performed by gently inserting the gastroscope through the mouth into the throat and down to the stomach. This procedure is done under sedation which allows the patient to be asleep and unaware of the procedure.
During a gastroscopy, the stomach will be inspected for any abnormalities. A thorough exam utilising narrow-band imaging and near-focusing examination will allow subtle abnormalities of the gastric lining to be discovered. This is particularly important in gastric cancer screening as Early Gastric Cancer (EGC) only manifests as subtle changes of the gastric lining. Gastric cancer screening programme has been shown to be useful in preventing gastric cancer in Japan and Korea.
In addition, biopsies will be taken during a gastroscopy for any suspicious features. A rapid test for H.pylori will also be conducted during the gastroscopy. The act of taking biopsies do not cause any discomfort nor pain.
Patients undergoing a gastroscopy will be given sedative drugs to minimise discomfort, reduce pain and some amnesia effect to minimise memories of the event.
Also, the patient will have a numbing anaesthetic agent sprayed to the back of the throat to minimise discomfort.
A gastroscopy is a safe and fairly straightforward procedure. Most patients regardless of age or underlying medical problems can undergo gastroscopy safely.
No bowel clearance is needed. The patient only needs to abstain from solid food at least 6 hours before and is allowed to continue to consume plain water till 2 hours before the gastroscopy.
There are very few alternatives to a Gastroscopy to investigate the stomach. Unfortunately, none of these alternatives is capable of evaluating for early gastric cancer.
A barium or gastrograffin dye study can be used to evaluate the stomach and oesophagus. This is more useful for diagnosing structural abnormalities and changes such as achalasia, oesophageal diverticulum, gastric herniation or large ulcers. Unfortunately, the dye study is unable to assess for any inflammation or changes to the lining of the stomach nor the presence of H.pylori and is certainly
unable to diagnose early gastric cancer.
A CT scan with distension of the stomach using an effervescence tablet is a variation of the barium/ gastrograffin dye study that is more sensitive and can pick up subtle changes both in and outside the stomach. Unfortunately, it has the same limitations in terms of assessment of the stomach lining and early gastric cancer.
It is important to note that gastroscopy is a very safe procedure. A typical restructured hospital regularly performs more than 50 gastroscopies a week.
The main complications are related to oesophagal, gastric perforation and post-procedure bleeding.
The perforation rate is estimated at 0.005% (5 perforations in 100,000 gastroscopies) while the bleeding rate ranges from 0.25-1.0%. The risk of over-sedation is very low and is reversible with medications.
There is no official consensus as yet worldwide regarding the interval for screening gastroscopy. The Japanese and Korean guidelines call for screening gastroscopy on a yearly to a two-yearly basis for anyone above 50 years of age with no risk factors.
For patients with findings of Intestinal Metaplasia or Barrett’s oesophagus, the screening interval can vary from 6 months to 2 years depending on the severity of the underlying abnormalities.