Endoscopy for neuroendocrine tumours (NETs)

An endoscopy is a test that looks inside the body. The endoscope is a long flexible tube which has a tiny camera and light on the end of it. Doctors use an endoscopy test to help diagnose certain types of neuroendocrine tumours.

Why you might have it

You are most likely to have an endoscopy to look at the inside of your:

• food pipe (oesophagus)
• stomach
• duodenum which is the first part of the small bowel that attaches to the stomach
• large bowel (colon)

This test can show what is wrong if you have abnormal bleeding, indigestion or difficulty swallowing.

A doctor or specialist nurse looks down the endoscope to see if there are any growths or other abnormal looking areas. The doctor or nurse can also take samples of any abnormal looking tissue through the endoscope (biopsies).

Gastroscopy

This information is about having an endoscopy of the oesophagus, stomach or small bowel (duodenum). This is also called a gastroscopy or oesophago gastric duodenoscopy (OGD).

Preparing for your test

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

Tell your doctor if you're taking medicines that changes how your blood clots. This inlcudes:

• warfarin or heparin
• aspirin
• clopidogrel
• 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 gastroscopy.

You can't eat for 6 hours before the test, but you might be able to drink sips of water up to 2 hours beforehand. Your doctor or nurse gives you written instructions about this before your appointment.

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

What happens?

Most people have a gastroscopy as an outpatient, which means you go home the same day. The test usually takes up to about 15 minutes. But expect to be in the hospital for several hours.

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.

Your nurse or endoscopist explains the procedure and asks 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 can usually have the test in your own clothes.

Usually you’re awake when you have the test, but you can choose to have medicine to relax you. These make you drowsy (sedation).

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 gastroscope.

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

Having the test awake

Your endoscopist sprays the back of your throat with local anaesthetic. 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 then lie on your left side.

It takes a few minutes for your throat to go numb. Your endoscopist passes the gastroscope into your mouth and down your throat to the oesophagus. The tube is slightly bigger 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 gastroscope on a television screen. They may put a small amount of air into the tube to help them see your oesophagus, stomach and duodenum. This might make you feel like burping.

Your endoscopist takes samples (biopsies) through the gastroscope of any abnormal areas. This shouldn’t be painful.

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

Having the test while drowsy

You lie down on the couch.

Your nurse 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 get more relaxed and drowsy. You are still able to follow instructions from your endoscopist and nurse.

They give you 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. 

Your endoscopist then passes the gastroscope down your throat. 

Endoscopic ultrasound

Sometimes an ultrasound probe is attached to the endoscope tube. This is called an endoscopic ultrasound. Ultrasound uses sound waves to build up a picture of the area. 

This test is used to look at the wall of the oesophagus, stomach, or the gallbladder and bile duct. It might help the doctors to get a better idea of the size of a tumour and how deep it has grown into the body tissues. They may also be able to see whether nearby lymph nodes are swollen (enlarged).

After your test

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 gastroscopy. This usually lasts for a few hours. 

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 to recover. You may not remember much (if anything) about the test. 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

Getting your results

You should get your results within 1 or 2 weeks at a follow up appointment. 

Waiting for test results can be a very worrying time. You might have contact details for a specialist nurse who you can contact 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.

Possible risks

A gastroscopy is a very safe procedure. Your nurse will tell you who to contact if you have any problems after the test. Your doctor will make sure the benefits of having a gastroscopy 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 hospital 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 your GP.

Damage to teeth

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

Other tests

Most people have several tests to diagnose a NET. You can find out what other tests you might have in your specific NET section.