Endoscopic Ultrasonography (EUS)

What is EUS?

Endoscopic ultrasonography (EUS) allows your doctor to examine the lining of your upper and lower gastrointestinal tract as well as some of the organs and structures located next to the GI tract The upper tract consists of the esophagus, stomach and duodenum; the lower tract includes the colon and the rectum. EUS is also used to study organs that are near the gastrointestinal tract, including the area around the lungs, the pancreas, gallbladder and bile ducts, and the liver

Endoscopists are highly trained specialists who welcome your questions regarding their credentials, training and experience. Your endoscopist will use a thin, flexible tube called an endoscope that has a built-in miniature ultrasound probe. Your doctor will pass the endoscope through your mouth or anus to the area to be examined. The ultrasound probe uses sound waves to create visual images of the digestive tract and adjacent structures.

Why is EUS done?

EUS provides your doctor with more information than other imaging tests by providing detailed images of your digestive tract. Your doctor can use EUS to diagnose certain conditions that may cause abdominal pain or abnormal weight loss.

EUS is also used to evaluate known abnormalities, including lumps or lesions, which were detected at a prior endoscopy or were seen on x-ray tests, such as a computed tomography (CT) scan. EUS provides a detailed image of the lump or lesion, which can help your doctor determine its origin and help treatment decisions. EUS can be used to diagnose diseases of the pancreas, bile duct and gallbladder when other tests are inconclusive or conflicting.

Why is EUS used for patients with cancer?

EUS helps your doctor determine the extent of spread of certain cancers of the digestive and respiratory systems. EUS allows your doctor to accurately assess the cancer’s depth and whether it has spread to adjacent lymph glands or nearby vital structures, such as major blood vessels. In some patients, EUS can be used to obtain a needle biopsy of a lump or lesion to help your doctor determine the proper treatment.

What can I expect during EUS?

EUS is generally well tolerated and does not usually cause pain or significant discomfort. Typically, your doctor will give you a sedative and/or a painkiller to help you relax and tolerate the examination. Most EUS examinations are done with you lying on your left side but positioning may vary depending on the area that needs to be examined. After you have received sedatives, your endoscopist will pass the ultrasound endoscope through your mouth, esophagus and stomach into the duodenum. The instrument does not interfere with your ability to breathe. The actual examination generally takes less than 60 minutes and patients are often asleep for the entire procedure. Many do not recall the procedure at all or have only a vague recollection of some gagging when the endoscope was inserted.

An EUS examination of the lower gastrointestinal tract can be performed safely and comfortably without medications, but many endoscopists prefer to give a sedative, especially if the examination is anticipated to be prolonged or if the doctor will examine a significant distance into the colon. You will start by lying on your left side with your back toward the doctor. Most EUS examinations of the rectum take less than 45 minutes to perform.

What happens after EUS?

If you received sedatives, you will be monitored in the recovery area until most of the sedative medication’s effects have worn off. If you had an upper EUS, your throat might be a little sore. You might feel bloated because of the air that was introduced during the examination.

You’ll be able to eat after you leave the procedure area, unless you’re instructed otherwise.

Your doctor generally can inform you of the preliminary results of the procedure that day, but the results of some tests, including biopsies, may take several days.

What are the possible complications of EUS?

Although complications can occur, they are rare when doctors with specialized training and experience perform the EUS examination. Bleeding might occur at a biopsy site, but it’s usually minimal and rarely requires follow-up. You might have a slight sore throat for a day or so. Nonprescription anesthetic-type throat lozenges help soothe a sore throat.

Other potential but uncommon risks of EUS include a reaction to the sedatives used, aspiration of stomach contents into your lungs, infection, and complications from heart or lung diseases. One major but very uncommon complication of EUS is perforation. This is a tear through the lining of the intestine that might require surgery to repair.

The possibility of complications increases slightly if a needle biopsy is performed during the EUS examination, including an increased risk of pancreatitis or infection. These risks must be balanced against the potential benefits of the procedure and the risks of alternative approaches to the condition.