Definition & Overview
Oesophagogastroduodenoscopy is a type of endoscopic procedure that provides visual images of the upper gastrointestinal tract and the duodenum. It is a useful technique for the examination and diagnosis of any abnormalities in these parts of the digestive system. Though commonly called EGD, this procedure is also known as panendoscopy or upper GI endoscopy.
The oesophagus is the part of the digestive system that connects the throat to the stomach. It is a muscular tube lined with a tissue called the mucosa. Aside from transporting food to the stomach, its upper sphincter also serves to keep food and other fluids from entering the airway. The lower oesophageal sphincter keeps ingested food and gastric acid from travelling back up.
The use of endoscopy to examine the oesophagus is widely preferred over other imaging techniques such as X-ray. This procedure is more accurate in terms of diagnosing any growth or abnormality, as it can also harvest tissue sample (biopsy) to determine if the abnormal growth is benign or not.
Who Should Undergo and Expected Results
Oesophagogastroduodenoscopy is typically advised for those suspected of suffering several conditions affecting the upper gastrointestinal tract. These include patients suffering from dyspepsia for a long time, heartburn, persistent vomiting, difficulty and pain in swallowing, nausea, anaemia with no clear and indicative cause, and inflammatory bowel disease. This procedure is also indicated for those who are suspected of having the Mallory-Weiss syndrome, which is characterised by a tear in the lining of the oesophagus. This type of endoscopy is also helpful in locating and identifying any abnormal growth in the region where the oesophagus joins the stomach as well as determining any swollen veins in the area.
People who are vomiting blood or excrete black-colored faeces are also required to undergo this endoscopic procedure for the diagnosis of hematemesis and melena.
Patients already diagnosed with Barrett’s oesophagus also undergo the procedure to regularly monitor the progress or worsening of their condition. This is characterised by the growth of simple columnar tissue instead of squamous epithelium in the lining of the oesophagus. This condition can eventually develop into oesophagal adenocarcinoma, a type of deadly cancer.
This procedure is also used for monitoring any ulceration in the stomach lining and duodenum. Patients who usually complain of upper abdominal pain, belching, occasional vomiting, and weight loss due to poor appetite can take advantage of this procedure to obtain correct diagnosis and treatment.
Patients who show symptoms of celiac disease are also advised to undergo this procedure for management. This condition is characterised as an autoimmune disorder manifested by chronic diarrhoea, distended abdomen, and loss of appetite.
Oesophagogastroduodenoscopy is also used as a means of transporting treatment modalities, such as injection therapy for bleeding lesions, surgical excision of tissue, photodynamic therapy, dilation of stenosis, placement of feeding tubes, and even the removal of foreign bodies that were accidentally ingested.
In some cases, people undergo ultrasound imaging also undergo this procedure for combined diagnosis and imaging.
EGD is considered a safe procedure, with results that help provide accurate diagnosis and monitoring of various oesophagal and upper stomach conditions. The patient is closely monitored for a few hours after the procedure, especially if sedatives were administered. They may also be asked to rest for a day or two, when necessary. A follow-up visit to the doctor’s office is often indicated to evaluate the results and proceed with treatment of diagnosed conditions.
How is the Procedure Performed?
Prior to the EGD, the patient is asked not to eat for at least 4 hours.
A local or general anaesthetic may be applied, depending on the need. The patient is then made to lie on the side and a mouth guard is placed to keep the mouth open and to protect the teeth in case the patient accidentally bites on the endoscope during the procedure. The endoscope is then inserted and guided into the pharynx and the oesophagus. Images are then collected as the endoscope travels into the stomach and the upper parts of the duodenum. The tip of the scope is also flexed to make a thorough examination of stomach parts such as the fundus and the gastroesophageal junction. If there is a need, a specialised device attached to the tip of the endoscope is used to collect tissue samples. Once completed, the air in the gastric area is aspirated and the endoscope is withdrawn.
Possible Risks and Complications
EGD is a highly useful diagnostic procedure but it is not without risks and complications. Most patients complain of soreness in the throat following the procedure and there is a possibility of bleeding in the gastroesophageal region.
During the procedure, some patients may experience difficulty in breathing that has to be immediately addressed by the physician. In some rare cases, patients develop aspiration pneumonia, a condition characterised by the inflammation of the bronchial tree following entry of foreign materials or fluid.
There is also the possibility of perforating the walls of the oesophagus and the stomach.
ASGE Ensuring Safety in the Gastrointestinal Endoscopy Unit Task Force, Calderwood AH, Chapman FJ, Cohen J, Cohen LB, Collins J, et al. Guidelines for safety in the gastrointestinal endoscopy unit.Gastrointest Endosc. 2014 Mar. 79 (3):363-72.
ASGE Standards of Practice Committee, Jain R, Ikenberry SO, Anderson MA, Appalaneni V, Ben-Menachem T, et al. Minimum staffing requirements for the performance of GI endoscopy. Gastrointest Endosc. 2010 Sep. 72 (3):469-70.