Endoscopic Ultrasound

An endoscopic ultrasound (EUS) is a specialized procedure that blends:

• Endoscopy — use of a scope to look at the inside lining of the gastrointestinal (GI) tract.
• Ultrasound — use of high frequency sound waves to see detailed images of the bowel wall and nearby organs or structures.

An EUS is performed by a gastroenterologist who has advanced training.

The EUS scope is a thin, flexible tube with a camera and a light on the end. A tiny ultrasound probe is also attached to the end of the scope.

An EUS is often performed as an outpatient procedure, like other endoscopic exams.

Most EUS cases are performed with sedation (medication that helps blocks pain and makes you feel sleepy). Your doctor will talk with you about the type of sedation used for your exam. If you get sedation, you will need someone to drive you home afterward.

An upper EUS looks at the upper GI system:

• Walls of the upper GI tract — esophagus (the tube that links your mouth and stomach), stomach and small intestine
• Nearby organs — pancreas, gallbladder and bile ducts
• Nearby structures — lymph nodes, tumors, cysts and blood vessels

A lower EUS looks at the lower GI system

• Bowel wall of your rectum and lower colon
• Nearby organs — bladder, prostate and uterus
• Nearby structures — lymph nodes and tumors
• Detailed images of the anal sphincter (muscles around the anus)

Fine needle aspiration (FNA)

If a tissue sample is needed, your doctor will use the ultrasound image to guide a thin needle through the endoscope to take a biopsy. You won’t be able to feel this.

Your doctor may have found a lesion or abnormality at a prior endoscopy study or on an X-ray test, such as a computerized tomography (CT) scan.

An endoscopic ultrasound (EUS) will allow your doctor to see very detailed ultrasound images of the lesion or abnormality. The bowel wall and nearby organs and structures (such as lymph nodes or blood vessels) can also be seen. If a biopsy (taking a small piece of tissue to look at under a microscope) is needed, fine needle aspiration (FNA) can be performed. Your doctor will use the ultrasound image to guide a thin needle through the endoscope to take the biopsy.

Your doctor may use an EUS to:

• Help with staging of cancer.
• Look at lesions (nodules) in the wall of the gastrointestinal (GI) tract.
• Look at the pancreas.
• Look at the bile ducts, gallbladder and liver.
• Find the cause of fecal incontinence.

There are important steps you must take to safely get ready for your endoscopic ultrasound (EUS). These are general instructions. Be sure to follow any instructions given to you by your doctor.

Your doctor or nurse will review the steps with you and make sure that you know how to get ready and what you can expect during and after the test. If you have any questions, be sure to bring them up with the doctor or nurse.

Getting ready for an upper EUS  is not the same  as getting ready for  a lower EUS. Be sure to ask your doctor which test you are having and how to prepare for it.