Endoscopic ultrasonography (EUS) is an examination of the upper and lower digestive tract. Upper EUS examines the esophagus, stomach, small bowel and surrounding organs such as the pancreas, liver, gallbladder and bile ducts. Rectal EUS examines the anal canal, rectum, and surrounding structures. Unlike conventional endoscopy that focuses on direct viewing of the lining of the intestinal tract organs, EUS uses ultrasound waves to indirectly look at the wall and adjacent structures beyond the lining of the gastrointestinal tract.
Your physician (also known as the endoscopist) uses a thin, flexible tube called an endoscope that has a built-in miniature camera and ultrasound probe. Your doctor will pass the endoscope through your mouth (or anus) to the area to be examined. Your doctor then will use the ultrasound to use sound waves to create visual images of the digestive tract.
EUS is only done at our affiliate institution, Tampa General Hospital. Upper EUS is done under sedation. For this reason, an adult driver is required to take you back home that day. Rectal EUS can be done comfortably without sedation. Immediately after the procedure, you may have mild sore throat but you should have no other symptoms. Diet and most medications can be resumed unchanged later that day. Your doctor will provide you with the results of the exam in the recovery area as you wake up from sedation; however, the results of any biopsies might take up to one week.
EUS is used to evaluate symptoms such as abdominal pain or abnormal weight loss, potential diseases of the pancreas, bile duct and gallbladder, or known abnormalities such as lumps or lesions which were detected at a prior endoscopy or were seen on x-ray tests such as a computed tomography (CT) scan. In the latter instance, the endoscopist can also sample the lump or lesion by directly inserting a small needle into the lesion to be later examined under the microscope. This is called fine needle aspiration (FNA) biopsy. Finally, EUS helps your doctor determine the extent of spread of certain cancers of the digestive and respiratory systems into adjacent lymph glands or nearby vital structures, such as major blood vessels. Most blood thinners such as heparin, Coumadin, and Plavix will need to be stopped for 5-7 days prior to EUS and FNA due to increased risk of bleeding. Other medications can be continued including aspirin and other non-steroidal anti-inflammatory medications (NSAIDs) prior to EUS and FNA. Antibiotics are usually not needed prior to EUS/FNA but your doctor will clarify that with you prior to the test.
Bleeding might occur at a biopsy site, but it’s usually minimal and rarely requires follow-up. 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 wall of the digestive tract that might require surgery to repair. The possibility of complications increases slightly if a needle biopsy is performed during the EUS examination.