Endoscopic ultrasound (EUS)

An endoscopic ultrasound combines an ultrasound and endoscopy. It can look at parts of your upper gastrointestinal tract. This includes the:

• food pipe (oesophagus)
• stomach
• pancreas
• bile ducts
• gall bladder
• first part of your small bowel (duodenum)
• lymph nodes 

An endoscopy is a test to look inside your body. Your doctor uses a long flexible tube called an endoscope. It has a tiny camera and light on the end. The endoscope also has an ultrasound probe at its tip. 

An ultrasound scan uses high frequency sound waves to create a picture of the inside of your body.

Why do you need an EUS?

You might have this test to:

• find out the cause of your symptoms

• find out how big a cancer is and whether it has spread

• take a sample of tissue (biopsy) that can help diagnose an abnormal area

• put in a small tube (stent) to open up a blockage

Preparing for your EUS

You usually have written information from the endoscopy staff explaining how to prepare for your endoscopy. It’s important that you read and follow the instructions. There is usually a number to call if you have any questions.

You might also have a pre operative assessment a few days before the test. This is to make sure you are well enough to have the test. It is also to give you information on how to prepare. 

You might have a blood test beforehand to check your blood levels and how well your blood clots.

Tell your doctor if you're having medicine that changes how your blood clots. This includes:

• aspirin

• clopidogrel

• arthritis medicines

• warfarin or heparin

• apixaban or rivaroxaban

• ticagrelor

Your doctor will tell you if you need to stop taking these or any other medicines for a while before your EUS.

You can't eat for 6 hours before the test but you might be able to drink sips of water up to 2 hours before your appointment. This will be explained to you beforehand and you will have written information. 

Talk to your doctor if not eating could be a problem for you. For example, if you have diabetes.

What happens?

You usually have an EUS in the hospital endoscopy department as an outpatient, which means you go home the same day. The test can often take between 15 to 45 minutes. But expect to be in the hospital for several hours to allow time for recovery. 

First you meet your nurse who asks you about your medical history and any allergies you might have. They may also take measurements such as your blood pressure and heart rate.

A doctor or a specialist nurse (endoscopist) does the test. They’ll first explain what they are going to do and ask you to sign a consent form. This is a good time to ask any questions you might have.

Some endoscopy units may ask you to change into a hospital gown. But you may be able to have the test in your own clothes.

If you have any false teeth or wear glasses you need to remove them for the test. Your nurse puts a plastic guard in your mouth to protect your teeth from the endoscope.

You usually have this test with sedation which makes you drowsy. Or you might have this test while you are awake but this is less common.  

This animation shows how you have an endoscopy, it lasts for 1 minute 19 seconds.

Having an endoscopic ultrasound

If you have sedation your nurse or doctor puts a small plastic tube (a cannula) into a vein in your arm. They then inject the sedative into the cannula. It takes a few minutes for you to be relaxed and drowsy. You are still able to follow instructions from your endoscopist and nurse.

You have local anaesthetic sprayed onto the back of your throat. This is to numb it and make it easier to swallow the tube. This may make you cough, your eyes may water and it may taste bitter.

You may have oxygen through a small plastic tube with prongs that sit just inside your nostrils. They also put a clip on your finger to check your oxygen levels and heart rate.

You lie on your left side to have this test. It takes a few minutes for your throat to go numb. Your endoscopist passes the endoscope into your mouth and down your throat to the oesophagus. The endoscope is slightly wider than a pen and will be uncomfortable but shouldn’t be painful.

They ask you to swallow as the tube goes down. They can see the images from the endoscope on a television screen. They may put a small amount of air into the tube. This distends the tummy a little and helps them see your oesophagus, stomach and duodenum more clearly. This might make you feel like burping.

Your endoscopist takes samples of any abnormal areas (biopsies) through the endoscope. This shouldn’t be painful. They may also take pictures using the camera within the endoscope.

At the end of the test, your endoscopist gently removes the endoscope.

If you have the test without sedation, you have the throat spray to numb the area beforehand, but you do not usually have a cannula. 

After your EUS

Your nurse or endoscopist will talk to you about how the test went. They'll tell you if they took any biopsies and when to expect the results. You might have some bloating and discomfort after the endoscopy. This usually lasts for a few hours. 

Your nurse will check your blood pressure, pulse, and oxygen levels.

If you haven’t had sedation, you can usually go home shortly after having the test. You won't be able to eat or drink until the local anaesthetic spray has worn off. This takes about an hour.

If you had sedation, you stay in the endoscopy unit for an hour or two until you are fully awake and recovered. Your nurse checks your blood pressure, pulse, and oxygen levels regularly. You need a friend or relative to take you home and stay overnight.

For 24 hours after having sedation, you shouldn't:

• drive

• drink alcohol

• operate heavy machinery

• sign any important documents

Possible risks

An EUS is a safe procedure, but your nurse will tell you who to contact if you have any problems afterwards. Your doctors will make sure the benefits outweigh the possible risks.

Some of the risks include:

Bleeding

If you have a biopsy you may have a small amount of bleeding. This usually stops on its own. If it doesn’t you might need to go into hospital to stop the bleeding.

Sore throat

This is common after having an endoscopy and lasts a few days. Contact the number provided or the hospital 24 hour advice line if you have severe pain in your throat, chest or tummy (abdomen).

Infection

There is a very small risk that after a biopsy the wound can become infected. If you have a temperature, feel hot and cold or shivery, or feel generally unwell, you should contact the hospital 24 hour advice line. 

Damage to teeth

There’s a small chance the endoscope can damage your teeth during the test. The mouth guard helps prevent this from happening.

Chest infection

There’s a small risk of breathing in spit (secretions) that you would normally swallow. This is because your throat is numb or from the sedation making you sleepy. Your nurse protects your airway by suctioning away any secretions during the procedure. 

Reaction to the sedation

Occasionally sedation can cause problems with your breathing, heart rate and blood pressure. The risks are higher in older people and those with lung or heart problems. Your nurse closely watches you for any problems during the test, so they can treat it quickly.

Tear or hole (perforation)

There’s a very small risk of the endoscope causing a tear in the lining of your oesophagus, stomach or duodenum. You might need an operation to repair this.

Getting your results

Before you go home, your doctor tells you if they have taken any biopsies. You should get your biopsy results within 1 to 2 weeks, but it may take longer. The specialist doctor at the hospital might give you your results. Or you might see your GP.

Waiting for test results can be a very worrying time. You might have contact details for a specialist nurse who you can speak to for information if you need to. It can help to talk to a close friend or relative about how you feel.

Contact the doctor who arranged the test if you haven’t heard anything after a couple of weeks.

More information

We have more information on tests, treatment and support if you have been diagnosed with cancer.