2016-06-16 18:18:58 UTC

Endoscopic Ultrasound (EUS) 101: What is an EUS?

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  • 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 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.
  • 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.


© AGA, September 2017

©AGA, July 2016

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