What is endoscopic ultrasound?
Endoscopic ultrasound (EUS) is a procedure that uses sound waves to create visual images of the digestive tract, including the pancreas.

Why is EUS used?
The images created from an EUS procedure are detailed ultrasound pictures of the pancreas, bile duct and digestive tract.  An EUS allows a doctor to determine the size and location of a tumor in the pancreas and whether the tumor has spread to nearby lymph nodes or invaded nearby blood vessels or other structures.  During this procedure, a thin needle that does not cause pain can also be passed through the endoscope into the tumor to obtain tissue samples.  This is a type of biopsy called fine-needle aspiration, or FNA.  Cells obtained from the biopsy are examined with a microscope to see if they are cancerous.

What happens during an EUS?
During an EUS, the patient lies on his/her side while an endoscope (a thin, lighted tube) with a small ultrasound probe built into the tip is passed through the patient’s mouth the stomach and into the  top part of the small intestine called the duodenum.  The tube will not affect the patient’s ability to breathe normally.  Once in place, the ultrasound probe uses sound waves to create images of the pancreas and surrounding structures.

Usually, the EUS procedure lasts 15 to 45 minutes and is considered by most patients to be mildly uncomfortable.

EUS is performed under heavy conscious sedation so the patient may feel drowsy, but will be awake during the procedure.

How does EUS compare with other techniques used to image the pancreas?
EUS is one of the most common imaging procedures used to diagnose pancreatic cancer.  It is often the best procedure to obtain samples of a tumor to make a definitive diagnosis of pancreatic cancer.  EUS may be able to find small pancreatic masses that have not been detected by computed tomography (CT) or magnetic resonance imaging (MRI) scans but suspected by the doctor as a result of symptoms and/or blood test results.  Studies show that EUS is equal to or better than CT scans for detection of early pancreatic cancer.

The patient’s experience during an EUS procedure is similar to that of an endoscopic retrograde cholangiopancreatography (ERCP), but the images produced are different.  EUS is generally a safer test than ERCP.

SonoFlex® EUS Endoscopic Ultrasound-Guided Aspiration Needle