Endoscopic Ultrasound (Endosonography, EUS)

What is it?

Endoscopic ultrasound (EUS) is a specialised examination that combines endoscopy and ultrasound. An ultrasound probe at the tip of the endoscope provides highly detailed images of the wall of the gastrointestinal tract and nearby organs.

EUS helps assess the pancreas, bile ducts, gallbladder, oesophagus, stomach, duodenum, nearby lymph nodes and other lesions. If necessary, a fine needle can be used during the examination to collect tissue samples for biopsy.

When is EUS performed?

Endoscopic ultrasound may be recommended:

• when pancreatic disease or tumours are suspected;
• to assess pancreatic cysts;
• to investigate stones or narrowing of the bile ducts;
• to determine the extent of gastrointestinal tumours;
• to investigate lesions beneath the lining of the oesophagus, stomach or duodenum;
• to collect tissue samples from lesions or enlarged lymph nodes;
• when other examinations have not provided a clear diagnosis.

How should you prepare?

• Do not eat or drink for 6–8 hours before the examination.
• If you take medicines that affect blood clotting, such as warfarin, apixaban, rivaroxaban, dabigatran or clopidogrel, make sure you tell your doctor. Do not stop taking any medicines on your own.
• Tell your doctor about any allergies, pregnancy and other significant medical conditions.

How is the examination performed?

• The examination is usually performed under sedation or general anaesthesia.
• The endoscope is passed through the mouth into the oesophagus, stomach or duodenum.
• Ultrasound is used to assess the internal organs and surrounding tissues.
• If necessary, a special fine needle is used to collect a tissue or fluid sample for laboratory examination.
• The examination usually takes 20–60 minutes.

After the Examination

• If you were given sedation or general anaesthesia, do not drive or make important decisions on the same day.
• Do not eat or drink until your doctor tells you that it is safe to do so.
• If a biopsy was performed, your doctor will explain when you can expect the results.

Is EUS safe?

Endoscopic ultrasound is a safe examination, and complications are rare. If a biopsy is performed, bleeding, infection or pancreatitis may occur in very rare cases. Before the procedure, your doctor will explain the potential benefits and risks.