Center for Digestive Health
ENDOSCOPIC ULTRASOUND (OR EUS)
Endoscopic ultrasound is a minimally-invasive procedure a specially-trained gastroenterologist may use to obtain high quality images of the internal organs inside your body (chest and abdomen). During EUS, a small ultrasound transducer embedded in a long, flexible tube called an endoscope is inserted into the upper digestive tract via the mouth or lower digestive tract via the anus. Unlike traditional ultrasound where sound waves are sent to the organ and back using a transducer positioned outside the body, endoscopic ultrasound allows the transducer to get close to the organs inside the body, thereby providing more detailed and accurate images.
Endoscopic ultrasound is used to examine the organs of the digestive tract and the surrounding tissue and organs. Information about the layers of the intestinal wall and adjacent areas including lymph nodes and blood vessels can also be obtained using EUS.
During the procedure, a tissue sample of suspicious tumors or enlarged lymph nodes may be obtained under EUS-guidance so that they may be examined under a microscope by a pathologist. This is called a fine needle aspiration (FNA), and is an alternative to exploratory surgery or other invasive testing.
What conditions does EUS diagnose?
Endoscopic ultrasound is especially useful in the diagnosing and staging of cancers of the esophagus, stomach, duodenum, rectum, pancreas, and sometimes lung. Information regarding the depth of penetration and spread of cancer to adjacent tissues and lymph nodes can be obtained using EUS. Masses or cysts of the pancreas and chronic pancreatitis may also be evaluated using EUS. Bile duct abnormalities, including stones in the bile duct or gallbladder can be studied using endoscopic ultrasound. The procedure is also useful for studying bile duct, gallbladder or liver tumors. EUS may help discover reasons for fecal incontinence when used to examine the sphincter muscles of the lower rectum and anal canal. Abnormalities, such as lesions or nodules that may be hiding in the intestinal wall beneath normal-appearing intestinal tract lining may also be studied using EUS (“submucosal” or “subepithelial” lesions).
Who is a candidate for EUS?
Patients who need to be evaluated for several digestive diseases including cancers of the esophagus, stomach, pancreas, small intestine, or rectum are candidates for endoscopic ultrasound. Patients with chronic pancreatitis, pancreatic cysts, and bile duct abnormalities including stones in the bile duct or gallgladder as well as those with liver tumors may also undergo EUS. Additionally, patients with a family history of pancreatic cancer may also be considered for screening with EUS.
EUS is often used to evaluate abnormalities including lumps or lesions which were detected during other tests such as X-rays or CT scans.
What will I need to do to prepare for the procedure?
Patients undergoing EUS may not have anything to eat or drink after midnight the night before the procedure. Enemas or laxatives will likely need to be taken by patients undergoing a rectal EUS. The procedure is performed with sedation on an outpatient basis. Patients need to arrange for someone to take them home and may not drive or return to work for 24 hours. It is important for your doctor to know what medications you are taking that may interfere with blood clotting (such as Coumadin) or platelet function (aspirin, Motrin, ibuprofen, Aleve and other NSAIDS). It is also important to tell your doctor about any allergies you may have to iodine or shellfish.
What will my recovery be like after the procedure?
Because of the sedation used during endoscopic ultrasound, you will be sleepy for up to an hour following the procedure. You will also be unable to walk or drink. For the rest of the day patients are advised to rest, sip fluids and eat light meals. Your throat may be mildly sore for a day or two and you may be temporarily bloated from the air that was pumped into your body to allow the doctor to view the organ in question. Call your doctor if you are having severe pain, vomiting, chills or fever or if you are experiencing passage or vomiting of blood.
What complications are associated with EUS?
Risks with EUS are quite rare, and the procedure is usually safe and well tolerated. Endoscopic ultrasound without fine needle aspiration has a complication rate of approximately one in 2,000, similar to the complication rate of other endoscopic procedures. Reactions to the medications used during EUS sometimes cause hives, skin rashes or nausea. The area of the vein where the IV was placed may develop a lump which usually resolves over time. Perforation of the intestinal wall is the main serious complication of EUS but this is quite rare.
Complications are seen more often when fine needle aspiration (FNA) is performed during EUS, but are still uncommon occurring in fewer than one percent of patients. These may include unusual bleeding caused by passing the needle through the gut wall, infection resulting from the aspiration of fluid from cysts or pancreatitis (inflammation of the pancreas) if the FNA is performed on the pancreas.
The information provided on these educational pages is for informational purposes only. The content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a qualified health provider with any questions you may have regarding a medical condition. And, if experiencing a medical emergency call 9-1-1.