Endoscopic Ultrasound (EUS)

Endoscopic ultrasound (EUS) is a diagnostic test that combines endoscopy and ultrasound to obtain images and information about the digestive tract and the surrounding tissue and organs.

Endoscopic ultrasound (EUS) is a diagnostic test that combines endoscopy and ultrasound to obtain images and information about the digestive tract and the surrounding tissue and organs. Endoscopy is a procedure that uses a scope to enter the body to visualize anatomy and help make a diagnosis.

The endoscope is a flexible tube containing a fiberoptic light fitted with a probe to take ultrasound images beyond what the physician can see when looking directly through the scope. Using high frequency sound waves, detailed images can be taken of organs that are anatomically near to where the endoscope is passing. The scope is most commonly inserted through the mouth to visualize the esophagus and stomach (upper GI endoscopy), but can also be inserted into the rectum to look at structures in the pelvis (colonoscopy/sigmoidoscopy).

What is endoscopic ultrasound with FNA?

A fine needle can be attached to the endoscope to collect fluids or tissue samples for laboratory and pathology tests. This is known as ultrasound guided fine-needle aspiration (FNA) and fine-needle biopsy.

This can help avoid having to pass a needle through the abdominal wall to obtain a biopsy.

Also using the needle, collections of fluid can be drained and medication can be delivered directly to a specific part of the body.

Endoscopic ultrasound can evaluate masses or swellings located within the walls of the esophagus, stomach, and rectum. It can also help assess the anatomy of organs and structures that are located near the esophagus or rectum.

What diseases can be detected by endoscopic ultrasound?

The endoscopic ultrasound can study the walls of the esophagus, stomach, and rectum. Because many adjacent organs are located in the same area, they can be examined by an appropriately-placed probe.

• With the ultrasound probe in the esophagus, the following organs can be evaluated:
  • Aorta
  • Lymph nodes in the mediastinum (the large compartment in the chest containing the heart, trachea, esophagus)
  • Lungs
  • Liver
  • Gallbladder and bile ducts
  • Pancreas
• With the ultrasound probe in the rectum, these structures can be evaluated:
  • Ovaries
  • Uterus
  • Bladder
  • The EUS can also evaluate the function of the rectal muscles to help diagnose causes of constipation.

EUS can also be used to look at lung cancers and detect swollen lymph nodes in the mediastinum.

Aortic aneurysms can also be detected and evaluated.

EUS is helpful in evaluating liver, gallbladder and pancreas diseases, swellings, masses, and stones.

In addition to these organs and structures, EUS can help evaluate masses, tumors, or swelling within the walls of the GI tract.

EUS is helpful in the staging of cancers of the esophagus, stomach, pancreas, and rectum. The prognosis of a cancer patient is related to the stage of the cancer at the time of cancer detection. For example, early-stage colon cancer refers to cancer confined to the inner surface of the colon before it is spread to adjacent tissues or distant organs. Therefore early-stage colon cancer can be completely resected with good chances for cure. However, if cancer is detected at later stages, the cancer tissues have already penetrated the colon wall and invaded neighboring organs and lymph nodes, or have spread to distant organs like the liver and lungs. EUS can measure how deep a cancer has penetrated into the bowel wall and whether it has spread to adjacent tissues and lymph nodes.

Does endoscopic ultrasound show the pancreas and pancreatic cancer?

Endoscopic ultrasound is one of the tools used to evaluate the pancreas and potential cancers. Because of its location behind the stomach and duodenum (the first part of the small intestine), abnormalities of the pancreas are usually diagnosed by laboratory tests and imaging like CT, MRI, and ultrasound.

EUS is able to provide more detailed images of the pancreas and its ducts, and is used in staging and monitoring responses to treatment. It is especially useful in patients with pancreatic ductal adenocarcinoma.

Are you sedated for endoscopic ultrasound?

Endoscopic ultrasound is most often an outpatient procedure that is usually performed under sedation.

As with any medical procedure, the physician will review the patient’s medical history, including medications and allergies, and perform a physical examination to ensure the procedure can be done safely.

Some medications, for example blood thinners, may need to be stopped for a short period of time before the procedure, if a biopsy or needle procedure is being considered. Only stop medications if advised to do so by your healthcare provider.

The patient will likely be asked to fast for at least 6-8 hours so that the stomach is empty. The physician will be able to inspect the lining of the esophagus and stomach both visually and with the ultrasound probe. An empty stomach decreases the risk of vomiting during the procedure.

If a rectal EUS is planned, the colon will need to be cleansed with a laxative regimen.

Because of the sedation that is required, the patient will need transportation home. They need to be observed until they are fully awake and functional. Driving or using machinery should be avoided until the patient is fully recovered.

Endoscopic ultrasound is usually performed with the patient sedated. Medication is given intravenously to make the patient comfortable and vital signs are monitored by the nursing staff.

Once the patient is comfortable, they are asked to swallow the fiberoptic endoscope, the flexible tube that contains a light, a camera, and an ultrasound probe.

The physician then threads the tube through the esophagus and stomach, examining the areas of interest, to help make the diagnosis. If there is a mass or swelling, a thin needle may be used to obtain a biopsy of a small piece of tissue that can then be sent for analysis. If fluid is present, it can potentially be drained.

How long does endoscopic ultrasound take?

There are three steps to most scheduled outpatient procedures, pre-op, the procedure, and post-op recovery.

Pre-op may take 1-2 hours for the nursing staff to start IV lines, place monitors, and ready the patient. It is the time that the physician will also visit, review the medical records, perform a brief physical examination, and answer any questions regarding the procedure.

The EUS procedure will take approximately 30-90 minutes depending upon what is found and the complexity of the situation.

Post-op may take 1-2 hours or more, depending upon how quickly the patient wakes up from sedation. The patient will need to be fully awake, able to drink fluids, urinate, and return to their baseline level of ambulation, most often they are able to walk on their own.

Is endoscopic ultrasound painful?

The EUS is not a painful procedure. Afterward, the patient may have a sore throat from the tube, or may feel bloated because air is puffed into the esophagus and stomach to help the physician visualize those structures.

Recover from the EUS is based upon recovery from the sedation. Most people tend to go home and sleep for the rest of the day, and are fully recovered by the next morning.

How risky is endoscopic ultrasound?

Endoscopic ultrasound is a safe procedure and complications are rare.

Most complications occur when a fine-needle aspiration or biopsy is required. These include infection, bleeding, or perforation (a tear) that may happen in an organ wall.

If a pancreas fine-needle biopsy is done, pancreatitis (pancreas inflammation) may occur.

Complication symptoms may include fever, vomiting, bleeding, and chest or abdominal pain.