What is endoscopic ultrasound?
Ultrasound examinations are normally carried out with an external device held to the skin which produces an image of what is in the body, for example to examine an unborn baby in a pregnant woman. Endoscopic ultrasound (sometimes referred to as EUS and also known as echo-endoscopy) is where a small ultrasound device is installed on an endoscope and inserted into the body. This results in better imaging than would be possible with an external ultrasound examination.
It is used primarily to examine the gastrointestinal tract, but can also be used to examine other tissue and organs, for example the lungs.
What is EUS used for?
Endoscopic ultrasound is a particularly useful to aid in the diagnosis and staging of...
- Problems with the pancreas (eg chronic pancreatitis, pancreatic cancer)
- Oesophageal cancer
- Gastric cancer
- Lung cancer
- Benign tumours/lesions in the upper gastrointestinal tract
- Problems with the gallbladder and liver (eg tumours or other abnormalities)
- Faecal incontinence (where there is accidental leakage from the bowel)
- Nodules/polyps in the wall of the intestine
- Rectal/anal cancer
- Bile duct stones (often in conjunction with ERCP)
What is involved in the procedure
As with other types of endoscopic procedures, an endoscope (or a colonoscope in the case of examination of the colon) is inserted into the body via the mouth (or anus for colonoscopy). The ultrasound device on the end of the endoscope produces sounds waves that create an image of the tissue in that area. In some instances a procedure called 'fine needle aspiration' may be used at the same time to extract fluid and tissue biopsies from lymph nodes or from any lesions.
The whole operation generally takes around 60 minutes.
What preparation is needed in advance?
If the EUS is being conducted in the upper gastrointestinal tract, you must fast before the procedure to make sure your stomach is empty. If EUS is being conducted in the rectum/colon, your bowels will similarly need to be empty. Advise your doctor of any medication you are taking, especially any blood thinning medications.
After the procedure make sure you do not drive or operate any heavy machinery on the same day, so it is strongly advised to have someone drive you home.