Endoscopic Ultrasound

Endoscopic ultrasonography is very useful in evaluating diseases involving the gastrointestinal (GI) tract and chest including abdominal symptoms and chest pain. You may want to consider an EUS if you have experienced:

• Pancreatic masses and tumours
• Pancreatic cysts
• Chronic pancreatitis
• Recurrent acute pancreatitis
• Bile duct stones
• Lymphoma
• Sarcoidosis
• Pain in the abdomen
• Accidental bowel leakage
• Unusual chest pain
• Unexpected weight loss

An EUS allows your endoscopist or doctor to examine organs and systems in the body that are usually unable to be seen through standard endoscopy procedures, CT or MRI scans. The ability to see detailed images of the digestive or respiratory system, using the ultrasound device, will allow your doctor to identify smaller issues within the body. EUS also allows endoscopists to take fluid or tissue samples using a thin needle passed through the endoscope. Benefits also include:

• No exposure to radiation.
• An accurate evaluation of tumour presence in a patient's abdominal walls to give an indication of oesophageal, gastric, rectal, pancreatic and lung diseases or cancers.
• Determine the stage or spread of cancer in organs, such as your lymph nodes.
• Ability to guide treatment of small cancer cells through accuracy of the ultrasound transducer.
• Provide a throughout evaluation of abnormal findings from MRI or CT scan.
• Guide the drainage and extrapolation of cysts and abnormal collections of fluid in the digestive tract.
• Ability to deliver medication that can be directly targeted to specific organs in the body such as the gall bladder, stomach lining, pancreas, liver and other organs.

It is important to recognise if you are a candidate for EUS. If you have previously had abdominal surgery which has modified your original anatomy such as some gastric bypass operations you will be unable to undergo an EUS.

You should not have anything to eat or drink for approximately 8 hours before your EUS. Typically, patients are asked to refrain from eating or drinking after midnight the night before their test to clear the procedure area. Sometimes, patients are asked to have a laxative or enema before the procedure to clear the gastrointestinal tract. Your doctor may ask you to hold any blood thinners for several days prior to the test as this may increase the risk of bleeding if fine-needle aspiration (FNA) is performed. It is important that you discuss your medications with your doctor prior to your test especially if you have chronic conditions, such as diabetes or high blood pressure.

On the day of your EUS an IV cannula will be placed in your hand or arm so that you can receive intravenous fluids, medications and sedatives during the procedure. Once you are brought into the endoscopy room, you will lay down on a comfortable bed, usually on your left side. Monitoring equipment such as a blood pressure cuff will be placed on your arm, an oxygen monitor will be placed on your finger, and ECG leads will be placed on your chest. A small nasal cannula will be placed in your nose to give you more oxygen during the procedure. A small plastic “bite block” will be placed in your mouth between your teeth, which protects your teeth and prevents any accidental biting of the scope during the procedure. Sedatives will be injected into your IV before the procedure begins. The echoendoscope will then be used with pinpoint accuracy, utilising the ultrasound probe, to examine the procedure area. This will involve examination inside the body using high-frequency sound waves to create clear images of abnormalities. The procedure usually lasts from 20-45 minutes. The vast majority of patients do not feel or experience any discomfort during the procedure, as they are usually asleep.

EUS is performed as an outpatient procedure which means that a patient can leave on the day of their appointment. When the procedure is finished, you will be brought to a recovery area where you will lay in bed until you are awake. Depending on the complexity of the procedure, the recovery process is between 30min – 2 hours. You will have an opportunity to discuss the results of the examination with your doctor on the day to gain more insight and advice about your condition. You will generally not require admission to the hospital. A specialist in digestive diseases (gastroenterologist) or lung disease (pulmonologist) with special training in EUS will interpret the EUS images. A doctor trained in analysing biopsies (pathologist) will report the test results if you have an FNA. Your doctor will discuss any important findings and next steps with you.

Like other endoscopic procedures, EUS is safe and well-tolerated. No procedure is without risk, but complications with EUS are quite rare. The complication rate for EUS without the fine-needle aspiration (FNA) is about 1:2000 (similar to the complication rate of other endoscopy procedures). The main complication of concern is perforation (making a hole in the GI tract) that can potentially be repaired endoscopically or may even require surgical repair. The chance of this become a serious complication is quite rare and all precautions are taken to avoid it. Infections are another rare complication of FNA. Infection can occur during aspiration of fluid from cyst; however, antibiotics may be given before the procedure to prevent this. A procedure involving a biopsy at the time of your EUS raises the chances of minor bleeding slightly. If unusual bleeding occurs, the patient may be hospitalised briefly for observation. If a biopsy or FNA is performed, bleeding, infection or inflammation of the pancreas (pancreatitis) may occur. This results in hospitalisation, observation, rest, IV fluid, and medication for abdominal pain which usually resolves spontaneously in a few days. You can reduce your risk of complications by carefully following your doctor's instructions for preparing for EUS. Contact your doctor or endoscopist if you experience any of the following symptoms:

• Fever
• Shortness of breath
• Pain in the chest
• Dark-coloured stool
• Abdominal pain

How long does an endoscopy ultrasound take?

An endoscopy ultrasound is a quick procedure usually taking from 20-45 minutes to fully examine a patient. After the procedure patients are required to stay in a recovery area for 30min – 2 hours before checking in with their doctor after their examination.

What is an EUS used for?

An EUS is used to find specific diseases in the upper gastrointestinal tract, chest and duodenum by utilising high-frequency ultrasound technology. EUS allows for detailed imaging and examination of these areas to evaluate different kinds of diseases within the body that MRI and CT scans cannot identify.

What is the difference between EUS and ERCP?

Both techniques are commonly used to examine organs and abnormalities within the digestive tract. However, the main difference between EUS and ERCP is that ERCP procedures utilise a video camera and EUS uses ultrasound utilises high-frequency sound waves to generate a virtual image.