Gastrointestinal system is comprised of multiple organs, extending from the mouth to the anus, that coordinate to perform numerous functions in a form of ten-meter structural complex.It is also close neighbor of many organs while extending from the chest cavity into the abdomen. It lies adjacent to the heart and major blood vessels in the chest cavity and important organs, such as liver, gallbladder, bile ducts, pancreas and spleen, in the abdomen.

               1- What is Endoscopic Ultrasound?

Upper and Lower GI endoscopy is used to visualize the inside of our digestive organs, such as esophagus, stomach, small intestines and colon. However, ultrasound is the only modality to see the inside of these organs through thin walls of the digestive system, although cross-sectional modalities, such as ultrasound, tomography and MRI, allow visualizing the neighboring organs exteriorly. This is called Endoscopic Ultrasound.  I hear you saying “We remember each of those terms”. Yes. Two systems that were used independently were combined and they became more effective to diagnose diseases of the digestive system. An ultrasound probe is attached to the endoscope that is used to look at the digestive system. Thus, we have a means to visualize all neighboring organs and tissues deeply.

               2- Which diseases can be diagnosed with endoscopic ultrasound? 

We may look at the inside and outside of the digestive system and diagnose benign and malignant conditions thereof. We may diagnose disorders of not only stomach, esophagus and intestines, but also pancreas, liver, gallbladder and bile ducts. This method also offers the most accurate diagnosis for very small gallstones that cannot be visualized with MRI.

               3- How does endoscopic ultrasound differ from other methods? What are the advantages and disadvantages in terms of comparison?

* The most significant advantage is the most accurate diagnosis of disorders of pancreas, gallbladder and bile ducts. It allows identification of small lesions that cannot be shown by other imaging techniques.

* It is superior to other modalities in diagnosis of lipoma originating from walls of esophagus, stomach and intestines as well as benign and malignant diseases originating from muscles.

* EUS is not solely used for diagnosis; it facilitates challenging therapeutic procedures, such as biopsy, nerve blocks (pain management in tumors) and drainage of pancreatic cysts.

* It can be used for treatment of gallstones and tumors that cannot be accessed through usual endoscopic routes.

* It allows local staging in almost all tumors of the digestive system.

               4- Which preparations are required for the procedure?

Patients require only fasting. A simple bowel cleansing is sufficient in case of an anal procedure. It is a comfortable method that is usually performed under sedation.

               5- How is endoscopic ultrasound performed?

This small tube is inserted into the mouth cavity and advanced to the stomach and the small intestines; inside of the digestive system is displayed on a monitor, while we can see the ultrasound images on another screen. If we see any suspicious tissue, a needle biopsy specimen can be taken using the hook attached to the device to finalize the diagnosis and perform the treatment, if deemed necessary.

               6- What should be taken into account after an endoscopic ultrasound?

Endoscopic ultrasound may take 30 to 90 minutes depending on the procedure. We monitor the patients for 1 to 2 hours after the procedure and discharge them on the same day, if there is no problem.