🔬 Upper GI Endoscopy

Upper Gastrointestinal Endoscopy (OGD) is a procedure used to visually examine the lining of the oesophagus, stomach, and duodenum. It is a critical diagnostic tool for dyspepsia, anaemia, and cancer screening, and provides a platform for therapeutic interventions such as haemostasis and biopsy collection. It is often performed under conscious sedation or local anaesthesia.

Indications include persistent dyspepsia despite medical treatment, 'red flag' symptoms (weight loss, iron deficiency anaemia, dysphagia, or persistent vomiting), and suspected upper gastrointestinal bleeding (haematemesis or melaena). It is also used for screening/surveillance of Barrett's oesophagus or gastric ulcers and for the histological diagnosis of coeliac disease via duodenal biopsy. It is indicated in those over 55 with new-onset dyspepsia.

The procedure is performed using a flexible endoscope (a thin, lighted tube with a camera). Patients are usually fasted for at least 6 hours. After the administration of a local anaesthetic throat spray and/or intravenous sedation, the scope is passed through the mouth, down the oesophagus, into the stomach, and through to the duodenum. Air is insufflated to distend the walls for better visualization. Biopsies can be taken using small forceps passed through the scope. The procedure typically takes 10-15 minutes.

A normal OGD (Oesophago-Gastro-Duodenoscopy) shows a healthy, pale-pink oesophageal mucosa without erosions or strictures. The gastro-oesophageal junction (Z-line) should be clearly defined. The stomach should have a regular rugal fold pattern, a smooth mucosal lining, and no evidence of ulcers or masses. The pylorus should be patent, leading into a duodenal bulb and second part of the duodenum with normal-appearing villi and no inflammation.

Interpretation involves a systematic visual inspection and the correlation of endoscopic findings with histological biopsy results. For example, a visual diagnosis of 'gastritis' must be confirmed by biopsy to identify H. pylori or autoimmune causes. Ulcers are graded based on their risk of re-bleeding (Forrest classification). In Barrett's oesophagus, the Prague criteria (C & M values) are used to measure the extent of metaplasia. All findings must be contextualised with the patient’s symptoms and history.

Abnormalities include oesophagitis (inflammation/ulceration), Barrett’s oesophagus (metaplastic changes), and oesophageal varices (dilated veins). In the stomach, findings may include peptic ulcers (gastric or duodenal), gastritis, or suspicious masses/malignancy. Hiatus hernias are frequently identified. In the duodenum, coeliac disease may be suggested by 'scalloping' or 'mosaic' patterns of the mucosa. Strictures, active bleeding sites, and signs of previous surgery are also documented.

OGD is a high-yield diagnostic and therapeutic tool. It is the gold standard for diagnosing upper GI malignancies and Barrett's oesophagus. Therapeutically, it is life-saving in the management of acute upper GI bleeds (e.g., through band ligation of varices or adrenaline injection/clipping of ulcers). It also allows for the monitoring of known conditions and the performance of minor procedures like dilatation of strictures or insertion of feeding tubes (PEG).

Inadequate sedation or poor patient tolerance can lead to a rushed or incomplete examination. Failure to retroflex the scope (looking back at the gastric cardia) can result in missing lesions at the top of the stomach or small hiatus hernias. Mistaking normal anatomy (e.g., the papilla of Vater) for an abnormality is an error for novices. Crucially, a 'normal' endoscopy does not rule out functional GI disorders or small-fibre pathologies not visible to the naked eye.

OGD only visualises the GI tract as far as the second part of the duodenum; it cannot assess the jejunum or ileum (which require capsule endoscopy or balloon enteroscopy). It is an invasive procedure with risks, including perforation and bleeding, particularly if biopsies or therapeutics are performed. Visualization can be obscured by recent food intake or heavy bleeding, sometimes necessitating a repeat procedure. Small or 'flat' lesions can occasionally be missed.

Key for MLA: Memorise the 2-week wait (2WW) referral criteria for OGD (e.g., dysphagia at any age; aged 55+ with weight loss and upper abdominal pain). Understand the management of acute GI bleed (Rockall and Glasgow-Blatchford scores). Remember that gastric ulcers must always be biopsied/followed up to ensure healing and exclude malignancy, whereas duodenal ulcers usually do not require biopsy for cancer.