The upper GI endoscopy, gastroscopy or oral panendoscopy is one of the most used diagnostic methods in the study of patients with gastro-intestinal diseases. It consists of the direct examination the throat (oropharynx), the esophagus, the stomach and first portion of the small intestine (duodenum) using a flexible camera called endoscope. The great advantage of this procedure is not only the direct visualization of any disease, but also the ability to obtain samples (biopsies) of the explored area that will aid in making a definitive diagnosis.
How is the exploration carried out?
The instruments used have improved notably since the introduction of the first endoscope almost 40 years ago. Today we use fine gauge endoscopes that are only 7 to 9 millimetres in diameter. The view from the camera is digitally enhanced and it displays high definition images on a TV monitor. This allows the doctor to obtain an extremely precise and reliable diagnosis.
Before the test, the patient must have had an empty stomach for at least six hours. This reduces the risk of aspirating stomach content into the lungs. Only in exceptional circumstances of extreme urgency will it be carried out without an empty stomach. This is usually an outpatient procedure. No hospitalization is needed except in cases were an intervention is necessary. Some of these interventions include sclerosis of esophageal varices, removal of polyps (polypectomies) and dilatation of narrowed areas of the bowel (stenosis).
The exploration can often be performed with only topical anesthesia sprayed in the throat. Occasionally, light sedation can be utilized using intravenous medications. During the procedure, the patient may develop some nausea. This is usually due to the introduction of air into the stomach that is required to adequately distend and visualize the organs. The unpleasant feeling is easily alleviated by burping.
Once the exploration is concluded the recovery is immediate, although there may be some soreness of the throat.
What is the upper GI endoscopy used for?
There are two uses for an upper GI endoscopy. First, it allows us to confirm or exclude the diagnosis of a number of digestive illnesses. Secondly, it permits certain therapeutic interventions such as obtaining biopsies or actually treating conditions such as bleeding from ulcers or dilating stenosis.
When should this test be carried out?
The indications are multiple:
Dyspepsia (pain or discomfort in the abdomen): This constitutes one of the most frequent indications, as it is the most usual reason for consultation. However, not all patients need the procedure. We do recommend it in all patients older than 45 and in those who present with anemia or weight loss.
Dysphagia: difficulties swallowing.
Odynophagia: pain with swallowing.
Persistent acid reflux or heart-burn despite medical treatment.
Monitoring of pre-malignant lesions of the esophagus such as Barrett's metaplasia.
Persistent nausea and vomiting, particularly of food from previous days.
Esophageal varices related to liver cirrhosis.
Disease of the bowel associated with poor absorption of nutrients.
Abnormal findings on X-ray studies such as gastric ulcers, polyps or tumors.
Which conditions can be treated through endoscopy?
A therapeutic endoscopy allows for the treatment of multiple conditions:
Polypectomy: This consists of the excision of small tumors called polyps from the wall of the bowel. It is carried out using a special probe that conducts electrical current and produces heat. It is completely painless but a blood clotting test must be done prior to the procedure to minimize the risk of bleeding.
Dilatation of a narrowing (stenosis): Chronic inflammation of the esophagus from acid reflux or the ingestion of caustics can cause severe narrowing of the esophagus. This is called stenosis and may impede adequate feeding. The gastroscopy allows the introduction of pneumatic balloons that, once placed in the narrowed segment of bowel, are inflated with air or water and widen the stenosis.
Removal of foreign bodies: When an object that cannot pass through the GI tract is swallowed it may remain trapped and cause an obstruction. Such is the case of the ingestion of batteries or coins, but also of certain food particles such as fish bones. The endoscope can easily retrieve these elements and prevent them from causing trouble
Control of bleeding ulcers: Until recently, ulcer bleeding was an indication for emergency surgery. Today, using endoscopy, we are able to control the bleeding by injecting agents directly into or around the ulcer or using a heat probe to cauterize it. If the bleeding is controlled in this manner, we avoid surgery, and later cure the ulcer disease with medications such as omeprazole that suppress the production of stomach acid.
Sclerosis and/or banding of esophageal varices: Patients with advanced liver cirrhosis often develop esophageal varices. These are dilated veins within the wall of the esophagus. They can cause severe and intense digestive bleeding. This is a life-threatening situation that requires immediate intervention. Using the endoscope, we are able to inject sclerosing agents that cause the varices to scar and stop bleeding. A newer technique enables us to place elastic bands around these veins to prevent them from bleeding. These techniques reduce the mortality from severe liver disease.
Which endoscopies must be done urgently?
An urgent endoscopy must be carried out in the following situations:
Severe upper GI bleeding.
Ingestion of caustics such bleach, etc.
Ingestion of foreign bodies causing obstruction.
Which factors interfere in the results of the procedure?
Performing the procedure without a completely empty stomach reduces its diagnostic ability as the digestive tract will not be clean and the view of the bowel will be impaired. The endoscopy under these conditions should only be carried out in an emergency.
Who should perform it?
The procedure must be performed by a specialist of the digestive tract with advanced training in endoscopy. He/she usually also has an assistant. An anaesthesiologist may be present if deep sedation or general anesthesia is required.
Does it require any special preparation on part of the patient?
The patient must have an empty stomach for at least 6 hours prior to the procedure.
Being calm and relaxed before the procedure is also beneficial.
What are the contraindications to performing an endoscopy?
The reasons to not perform the procedure are relatively few:
Perforation or suspicion of perforation of the bowel.
Relative contraindications: These include:
History of a recent heart attack or stroke, respiratory insufficiency, advanced age or severe clotting disorders. All these should be considered on an individual basis with careful balancing of risks and benefits.
Which complications may this procedure have?
An upper endoscopy is a very safe procedure. Complications occur in only 0.2% of patients. The mortality is also very low and reaches only 0.01%. Among the serious complications it is necessary to highlight:
- Perforation of the esophagus and the stomach.
- Aspiration of stomach content into the lungs
Is the sedation necessary before beginning the exploration?
There is usually no need for sedation for an upper endoscopy. The procedure can generate some anxiety to the patient. However, due to advances in technology, patient discomfort is minimal as smaller endoscopes are used. Also, the procedure has a very short duration (between 5 to 10 minutes) which increases the tolerance.
The benefits of intravenous sedation are debatable. It is usually only used in urgent cases or for patients with pre-existing conditions.