Describe the important anatomical narrowings of the oesophagus

The oesophagus is a muscular tube approximately 25 cm long from the pharynx to the stomach. There are four anatomical narrowings to the oesophagus, these are listed proximal to distally. They may be visualised on oesophago-gastroduodenoscopy (OGD) and are also the regions where foreign bodies may lodge and perforation are most likely to occur:

• Cricopharyngeal muscle

• Aortic arch

• Left main bronchus

• Lower oesophageal sphincter

What is an OGD and what are the advantages compared to contrast imaging?

OGD is the passage through the upper gastrointestinal (GI) tract using a flexible steerable fibre-optic telescope, which allows for direct visualisation of the tissues. The advantage over radiology is that a direct visualisation is achieved, early malignancies are detected (biopsy), exact identification of bleeding ulcers is achieved and therapy may be instituted.

What other therapies may be achieved during an OGD?

• Treatment of oesophageal strictures with dilatation techniques. The endoscope is passed into the oesophagus, the stricture is visualised and a wire passed through the stricture. The endoscope is then removed and increasing sized plastic dilators passed over the wire through the stricture until satisfactory clearance is achieved.

• Duodenoscopy allows for treatment of biliary tract disease.

• Percutaneous endoscopic gastrostomy (PEG) tube insertion.

4 Describe the steps undertaken in performing an OGD for a bleeding peptic ulcer

It must be first decided if the bleed is a low risk or high risk (e.g. Rockwall scoring system). If high-risk then an urgent OGD must be performed, if low-risk group the OGD should be done within 24 hours.