Endoscopic ultrasound (EUS) is a minimally invasive procedure to assess digestive and lung diseases. A special endoscope uses high-frequency sound waves to produce detailed images of the lining and walls of your digestive tract and chest, nearby organs such as the gall bladder, kidney, pancreas, liver, and lymph nodes. This procedure can also be combined with a procedure called fine-needle aspiration which allows your doctor to sample (biopsy) fluid and tissue from your abdomen or chest for analysis. EUS with fine-needle aspiration can be a minimally invasive alternative to exploratory surgery.
EUS provides you doctor more detailed pictures of your digestive tract anatomy. Your doctor can use EUS to diagnose the cause of conditions such as abdominal pain or abnormal weight loss. If your doctor has ruled out certain conditions, EUS can confirm your diagnosis and rule out other inconclusive results. EUS can also be combined with a procedure called fine-needle aspiration which allows your doctor to sample (biopsy) fluid and tissue from your abdomen or chest for analysis. EUS with fine-needle aspiration can be a minimally invasive alternative to exploratory surgery. EUS can also help in the following situations: 1. Assess how deeply a tumor penetrates your abdominal wall in esophageal, gastric, rectal, pancreatic and lung cancers 2. Determine the extent (stage) of cancer, if present 3. Determine if cancer has spread (metastasized) to your lymph nodes or other organs 4. Provide precise information about non-small cell lung cancer cells, to guide treatment 5. Evaluate abnormal findings from imaging tests, such as cysts of the pancreas 6. Guide drainage of pseudocysts and other abnormal collections of fluid in the abdomen 7. Permit precise targeting for delivering medication directly into the pancreas, liver and other organs
- EUS allows doctors examine organs and other structures that can’t be seen through standard endoscopy procedures.
- Because the ultrasound device is inside your body, right next to your organs, it may create more detailed and accurate images. During traditional ultrasound exams, sound waves must travel from outside your body.
- EUS allows your doctor to collect tissue or fluid samples by passing a thin needle through the endoscope. This eliminates the need for a separate biopsy procedure.
- EUS will not expose you to radiation
- EUS is a generally safe procedure, but a bit invasive due to its nature of having to be passed into a patient's GI system; mouth or anus. This may cause discomfort in some patients.
During the procedure, Your endoscopist will pass a thin, flexible tube called an endoscope through your mouth or anus to reach the area that needs to be examined. Your doctor then will turn on the ultrasound component to produce sound waves that create visual and precise images of the surrounding tissue [including lymph nodes in the chest]. Once this is completed, the endoscope will be gradually withdrawn If the procedure involves a fine needle aspiration: your doctor may need to pass a second, curved device through a channel in the endoscope into your digestive tract. That device can guide a very slender needle to your lymph nodes and tumors or other abnormalities. The needle extracts fluid and tissue for analysis. EUS with fine-needle aspiration generally lasts less than an hour.
Inform your doctor in advance about all medications that you’re taking and about any allergies (especially Latex) you may have to medications. He / she will tell you whether or not you can continue to take your medication as usual before the EUS examination. For an EUS of the upper gastrointestinal tract, you will be required to fast approximately six hours before the examination. Your doctor will tell you when to start fasting. For an EUS of the rectum or colon, your doctor will instruct you to either consume a large volume of a special cleansing solution or to follow a clear liquid diet combined with laxatives or enemas prior to the examination. The procedure might have to rescheduled if you do not follow your doctor’s instructions carefully.
A specialist in digestive diseases (gastroenterologist) or lung disease (pulmonologist) with special training in EUS will interpret the EUS images. A doctor trained in analyzing biopsies (pathologist) will report the test results if you have fine-needle aspiration. Your doctor will discuss any important findings and next steps with you.
Like other endoscopy procedures, EUS is safe and well tolerated. Complication rate for EUS without the fine needle aspiration is about one in two thousand. This is similar to the complication rate of other endoscopy procedures. Sometimes, patients can develop reactions such as hives, skin rash or nausea to the medications used during EUS. The main complication of serious note is gastric perforation that may require surgical repair in the worst case. This is quite rare and all precautions are taken to avoid it. When FNA is performed complications occur more often 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 hospitalized briefly for observation, but blood transfusions are rarely needed. Infection is another rare complication of FNA.
Why is a fine needle aspiration performed during the EUS?
If a tissue sample is suspected by the doctor, he or she will use the ultrasound image to guide a thin needle through the endoscope to take a biopsy. This will be sent for analysis and will assist in providing an accurate diagnosis for you. You won’t be able to feel this.
What internal organs can an EUS provide information on?
EUS can provide valuable information about your esophagus, bowels, lymph nodes, pancreas, liver, gall bladder and bile ducts.