What is an Endoscopic Ultrasound (EUS)?
An Endoscopic Ultrasound (EUS) is a type of endoscopic examination. The process involves the insertion of a thin tube into the mouth and down into the stomach and the first part of the small intestine.
At the tip of the tube, there is a small ultrasound probe present that emits sound waves. These sound waves bounce off of the surrounding structures, such as the stomach, small intestine, pancreas, bile ducts, and liver. These sound waves are then recaptured by the probe and converted into black and white images that are then interpreted by the doctor.
Because the pancreas sits next to the stomach and small intestine, Endoscopic Ultrasound (EUS) allows the physician to get very detailed images of the pancreas. Endoscopic Ultrasound (EUS) is typically performed in an outpatient setting and usually takes between 30 and 45 minutes.
What are the reasons why the patient needs an Endoscopic Ultrasound (EUS)?
Endoscopic Ultrasound (EUS) allows for very detailed imaging and analysis of the pancreas. As such, it is an impressive test for calculating many different kinds of diseases that can occur in the pancreas. Examples of such pancreatic conditions for which Endoscopic Ultrasound (EUS) can be extremely useful are:
One of the most common reasons that patients can be referred for an EUS of the pancreas is to evaluate abnormal findings on a CT (CAT scan), MRI, or ultrasound of the abdomen, or for more investigation of abnormal blood tests such as elevated liver function tests (AST, ALT, bilirubin) or elevated pancreatic enzymes (amylase, lipase).
Patients with specific types of abdominal pain may also be referred for an Endoscopic Ultrasound (EUS). Examples of reasons for referral for an Endoscopic Ultrasound (EUS) include:
- Dilated pancreatic duct
- Dilated bile duct
- Swollen/inflamed pancreas
- founded stones in the pancreas duct or bile duct
- founded blockage of the pancreas or bile duct
These findings listed above can be caused by both benign and malignant conditions. Thus, it is important that the patient discuss the reason for the Endoscopic Ultrasound (EUS) with his physician.
Can biopsies of the pancreas be taken at the time of the patient’s Endoscopic Ultrasound (EUS)?
One of the advantages of performing an Endoscopic Ultrasound (EUS) is that pancreatic biopsies can be obtained at the time of the examination. These types of biopsies often referred to as FNA, or fine-needle aspiration can allow for the physician to collect tissue samples which can later be analyzed under a microscope.
Special needles which are designed to be used with the Endoscopic Ultrasound (EUS) scope, allow the doctor to insert a small needle through the wall of the stomach or intestine directly into the pancreas.
Because this is done at the time of the Endoscopic Ultrasound (EUS), the physician is able to direct the needle to the exact location of interest all while watching the needle with the Endoscopic Ultrasound (EUS).
FNA (fine-needle aspiration) is most commonly performed to calculate masses or tumors of the pancreas and in order to determine if cancer is present. Another very common reason for performing an FNA (fine-needle aspiration) is in the evaluation of pancreatic cysts.
In such situations, the needle is used to sample the fluid which is contained in the cyst. This fluid can further be sent for biochemical, cytologic, and molecular analysis in order to help characterize the type of pancreatic cyst the patient has.
In certain cases, larger biopsy samples of the pancreas may be required. Endoscopic Ultrasound (EUS) allows the physician to obtain “core biopsies” of the pancreas in a similar fashion to FNA.
Are there any risks of having an Endoscopic Ultrasound (EUS)?
There is a risk for cardiac or pulmonary complications during an Endoscopic Ultrasound (EUS) procedure because sedation or in some cases general anesthesia is used during Endoscopic Ultrasound (EUS).
As with any of the endoscopic procedure, there is a small risk of causing bleeding or a tear of the GI tract (called a perforation). These types of complications can often be managed endoscopically however, emergency surgery may be required in the worst-case scenario.
Fortunately, the risk of a severe complication like this from Endoscopic Ultrasound (EUS) is very low, less than 1% in most of the cases.
What should the patient expect on the day of his Endoscopic Ultrasound (EUS)?
On the day of the patient’s Endoscopic Ultrasound (EUS), he will arrive in the endoscopy suite. An IV catheter will be placed in the patient’s hand or arm so that he can receive intravenous fluids and sedatives during the procedure.
When the patient is taken to the endoscopy room, he will lay down on a bed, usually on the left side. In order to monitor the patient’s vital signs during the procedure, a blood pressure cuff will be placed on his arm, an oxygen monitor will be placed on his finger, and EKG leads will be placed on his chest.
A small nasal cannula will be placed in the patient’s nose to give him oxygen during the procedure. A small plastic “bite block” will be placed in the patient’s mouth between the teeth, which protects teeth and prevents any accidental biting of the scope during the procedure.
When the procedure is finished, the patient will be brought to a recovery area where he will lay in bed until he is awake. The patient’s important signs will continue to be monitored during this time.
Before the patient is discharged home, he will have an opportunity to meet with the physician to discuss the results of the Endoscopic Ultrasound (EUS) and receive further instructions regarding the medications.