What is EUS and why is it peformed?

Endoscopic ultrasonography (EUS) allows your doctor to examine your esophageal and stomach lining and is often used to examine other organs that are near the gastrointestinal tract such as the liver, pancreas and gall bladder. EUS can also be used to further assess abnormalities of the colon or rectum.

Your doctor will use a thin, flexible tube called an echoendoscope that has a built-in miniature ultrasound. Your doctor will pass the echoendoscope through your mouth or anus to the area to be examined. Your doctor then will use the ultrasound waves to create images of the area that being examined.

EUS is commonly used to further assess abnormalities detected by other tests such as CT scans, MRI or even gastroscopy and colonoscopy. In some instances EUS is used to take needle biopsies of abnormalities which can be used to confirm or rule out cancer. In cases of an established or suspected cancer, EUS can help define the extent of the cancer which may help your doctor(s) decide on the correct treatment.


What preparations are required?

An empty stomach is required for a thorough and safe EUS examination of the upper gastrointestinal tract. Some medications may need to be discontinued before EUS. Specific details about how to prepare for EUS of the upper gastrointestinal tract can be found here. Specific details about how to prepare for EUS of the lower gastrointestinal tract can be found here.


Do I need to take antibiotics?
Your doctor might prescribe antibiotics if you are having specialised EUS procedures, such as drainage of a collection or a cyst.


What can I expect during EUS?

Your doctor will first discuss the risks of the procedure with you and address any questions you may have. You will then meet your anaesthetist who will discuss all aspects of the anaesthetic. Following this you will be taken to the procedure room. You'll then lie on your side, and a needle will be placed in your hand or arm. This is used to administer the anaesthetic. Once you are completely asleep your doctor will pass the echoendoscope through your mouth and into the oesophagus, stomach and duodenum for EUS of the upper gastrointestinal tract. For EUS of the lower gastrointestinal tract tract the echoendoscope will be inserted through the anus. The procedure usually takes around 45-60 minutes.


What happens after EUS?

You will be monitored until the anaesthetic has worn off. Your doctor will explain the results of the examination to you and will provide you with a written report of your procedure for your GP. You will be able to eat after you leave unless your doctor instructs you otherwise. Because of the anaesthetic, your judgement and reaction time will be impaired for the rest of the day. You will need someone to drive you home and stay with you.


What are the possible complications of EUS?

EUS is an extremely safe procedure when performed by doctors who are specially trained and experienced in the technique, however there can be rare complications.

If a needle biopsy is undertaken there is a 1 in 200 risk of bleeding. Needle biopsies of the pancreas also carry a 1 in 200 risk of pancreatitis. This usually manifests as abdominal pain and usually settles with a period of bowel rest/fasting for 24-48 hours. Pancreatitis may occasionally require admission to hospital and rarely may lead to life threatening complications. Perforation or a tear in the lining of the gastrointestinal tract may occur (1 in 1000 procedures) and this usually requires surgery. Drainage of fluid collections with EUS carries a small risk of infection which is reduced when antibiotics are used.

Although serious complications after EUS are uncommon, it's important to recognise complications and treat them early.

Contact your doctor immediately if you have a fever after the test or if you have persistent abdominal pain, or bleeding, including black stools. If you have any concerns following your test, you should contact your doctor right away.