What is an Endoscopic Ultrasound (EUS)?
Endoscopic ultrasound (EUS) is an advanced endoscopic procedure for the examination of the pancreas, bile duct, gallbladder, lymph nodes and lesions arising from the deeper layers of the wall of the gastrointestinal tract. EUS may be performed to evaluate abnormalities such as pancreatic masses or cysts seen on imaging tests (e.g. CT, MRI or ultrasound scan), submucosal lesions or “lumps” detected at a prior endoscopy or to investigate patients with recurrent pancreatobiliary pain or pancreatitis of unknown cause.
How do I prepare for an EUS?
An empty stomach is essential for a safe procedure, so you should have nothing to eat for six hours beforehand. You can continue to drink ‘clear fluids’ only (i.e. water, clear fruit juice without pulp, cordial, black tea/coffee WITHOUT milk, Gatorade/sports drinks, soft drinks) up until two hours prior to your procedure. After that you must remain nil by mouth apart from a sip of water with any important regular medicines (but do not take any diabetes medications).
Patients taking diabetic or blood thinning medications should inform their Gastroenterologist as they may require specific instructions.
How is an EUS performed?
Deep sedation is administered by an anaesthetist prior to your procedure so that you are comfortable. Once sedated and lying comfortably on your left side, the echoendoscope (a flexible tube with ultrasound probe at the distal end) is passed through your mouth and into the oesophagus, stomach, and duodenum. Your Gastroenterologist will then use ultrasound to visualise the digestive tract wall and digestive organs (i.e. pancreas, bile duct, gallbladder, liver, lymph nodes). Biopsies and other interventions may be performed under ultrasound guidance. The procedure usually takes approximately 30 minutes to complete.
What happens after an EUS?
Following the procedure, you will remain in the recovery area for an hour or so until the sedation medication wears off. Your Gastroenterologist will briefly inform you of your test results on the day of the procedure and if necessary, a follow-up appointment may be made to discuss the test results in more detail.
Because of the sedation medication given during the procedure, it is very important that you do not drive a car, travel on public transport alone, operate machinery, sign legal documents or drink alcohol within the first 24 hours after the procedure. After 24 hours you can return to work and resume normal activities. It is mandatory that a responsible adult accompanies you home and stays with you overnight.
What are the risks or side-effects?
Although complications can occur with any procedure, they are very infrequent after EUS. Common side-effects may include a mild sore throat or abdominal discomfort which should resolve within an hour or so. The risk of perforation (hole in the wall of the gastrointestinal tract) following diagnostic EUS are estimated at 0.1% or less. Surgery may be required to repair a perforation. The rate of complications may be higher for patients undergoing therapeutic procedures compared with those undergoing diagnostic procedures. If fine needle biopsy is performed the risk of abdominal pain is approximately 5% and more serious complications may include pancreatitis (0.4% of cases), bleeding (0.1%) or infection (1%). Whilst extremely rare, there have been case reports of tumour seeding along the biopsy tract after EUS biopsy of cancers. Whilst EUS is an accurate way to examine the pancreas and upper gastrointestinal tract, it is possible that small but significant lesions may be missed. Like all medical procedures, there is a remote chance that a significant complication can result in death, however this is exceedingly rare (2 in 10,000 cases) following EUS.