EUS is a low-risk diagnostic procedure. It combines two procedures:
- Endoscopy, during which your doctor inserts a thin, lighted tube into your body
- Ultrasound, which uses high-frequency sound waves to obtain detailed images
EUS uses a special endoscope with an ultrasound probe attached. We use EUS to evaluate and diagnose upper and lower digestive tract disorders. The procedure takes approximately 30minutes. You can return home when it is finished.
Your doctor may use EUS to help diagnose a number of digestive disorders. EUS provides your doctor with detailed images of your internal structures. Your doctor may use it to:
- Detect small tumors in the pancreas
- Stage gastrointestinal cancers (determine how severe the cancer is)
- Detect stones in the biliary or pancreatic ducts
Your doctor may perform fine-needle aspiration during EUS to perform a biopsy. He or she will thread a thin needle through the endoscope to remove some tissue samples and send them to a lab for analysis. Biopsy can determine the presence of cancer.
Before your procedure, you will need to follow specific preparation instructions. Your doctor will discuss them with you in detail. Preparation instructions include:
• If you are having EUS of the upper gastrointestinal tract, you may not eat or drink for six to eight hours prior to your procedure. This ensures that your tract is clear of food products.
• If you are having EUS of the lower gastrointestinal tract, you will need to follow a liquid diet followed by an enema or laxative preparation.
• Tell your doctor if you have any allergies.
• Your doctor will instruct you regarding any prescription medication you take.
On the day of the procedure, arrive one hour before your EUS is scheduled to start. Make sure a responsible adult accompanies you in order to take you home when it is finished.
- We will insert an IV into your vein in order to administer fluids and sedative.
- Your doctor will pass the endoscope through your tract, through either your mouth (upper gastrointestinal) or your rectum (lower gastrointestinal).
- Your doctor observes the images on a nearby monitor.
- Your doctor performs a biopsy, if necessary.
Once the procedure is finished, you will need to recover from the sedatives. Your doctor will discuss the findings with you. Then you may go home, and you should rest for the remainder of the day.
Like other endoscopy procedures, EUS is safe and well tolerated. No procedure is without risk, but complications with EUS are quite rare. Complication rate for EUS without the fine needle aspiration is about 1:2000 (similar to the complication rate of other endoscopy procedures). The main complication of serious note is perforation (making a hole in the intestinal wall) that can potentially be repaired endoscopically or may even require surgical repair. This is quite rare and all precautions are taken to avoid it.
When FNA (biopsy) is performed there is a slightly higher risk of complications but are still uncommon (0.5-1.0%). Passing a needle through the gut wall may cause minor bleeding. If unusual bleeding occurs, the patient may be hospitalised briefly for observation, but blood transfusions are rarely needed. Infection is another rare complication of FNA. Infection can occur during aspiration of fluid from cysts and antibiotics may be given before the procedure. If the FNA is performed on the pancreas, pancreatitis (inflammation of the pancreas) can rarely occur. Pancreatitis calls for hospitalization, observation, rest, IV fluid, and medication for abdominal pain which usually resolves spontaneously in a few days