With endoscopic ultrasound (EUS), doctors utilize specialized endoscopes which have a camera and light as well as an ultrasound probe. This allows precise and detailed images of the upper and lower digestive tract as well as the surrounding structures and organs. Even some areas which are deep inside the body such as the pancreas, bile ducts, and liver can be easily visualized. EUS can be used to perform biopsies, for diagnostic imaging and staging of tumors. It is also used in some therapeutic procedures including injecting medication, draining cysts, unblocking bile ducts and placement of small markers for radiation treatment of some cancers.
The endoscope with ultrasound is a long flexible tube with a camera, light and ultrasound transducer. There is a channel inside the scope that allows instruments to be passed through it to take biopsies, drain fluid and place stents.
Reasons for EUS
EUS can be used to investigate symptoms including abdominal or chest pain, abnormal weight loss, and fecal incontinence. Diseases of the pancreas and bile ducts can often be diagnosed by EUS. It is often used to evaluate abnormalities detected on imaging studies including CT, MRI or PET scans. It is highly accurate at providing local staging for many types of cancer including esophageal, stomach, duodenal, pancreatic, liver, rectal and lung cancer. EUS can also be used in some therapeutic procedures including injecting medication, draining cysts, unblocking bile ducts and placement of small markers for radiation treatment of cancer.
For an upper endoscopic ultrasound, the stomach needs to be empty. You will not be able to eat or drink after midnight the night before the procedure. You may be asked to stop taking blood-thinning medications such as coumadin, plavix, eliquis, pradaxa, or others for several days before. You will be given instructions regarding medications for diabetes while you are fasting. You can take essential medication such as blood pressure medication with a sip of water on the morning of the procedure.
For a lower endoscopic ultrasound, you will also need to be fasting after midnight. You may have to take a bowel cleansing preparation as you would for a colonoscopy, or take an enema on the morning of the test.
Specific instructions for preparation will be provided beforehand by your physician or their associate.
When you arrive at our endoscopy center, you will be greeted by a receptionist who will register you. You will be brought to a pre-procedure area where you will change into a gown, have an intravenous line placed and you will be seen by a nurse and your physician. You will be brought into a procedure room where you will be placed on monitoring equipment and given sedation. The procedure will be completed and you will be brought to the recovery area where your physician can discuss any important findings and review next steps. If biopsies are taken, those results will not be available immediately.
Side Effects and Risks
Some patients may experience a mild sore throat after the procedure. Significant risks are rare but can include bleeding, infection or inflammation, aspiration or reaction to medication. Very rarely, an injury to the digestive tract or perforation can occur. In some situations, this can be treated by endoscopy and some times surgery is needed.
Other imaging tests such as CT, MRI, PET scans as well as external ultrasound can provide some of the same diagnostic information as EUS. In some situations, a radiologist can use external imaging to perform biopsies and place drains or stents.