Endoscopic ultrasonography (EUS) is an imaging modality for the examination of the digestive tract. The procedure utilizes a dedicated endoscope equipped with an integrated camera and an ultrasound probe at its distal extremity, inserted into the digestive tract –commonly through the esophagus, stomach, or rectum. The technique facilitates the direct visualization of the internal surface while simultaneously enabling the detailed assessment of subjacent organ and tissue structures utilizing ultrasonic waves.
EUS provides a detailed view of the digestive tract and nearby organs. The circumvention of interfering factors, namely the skin, subcutaneous adipose tissue, and intestinal gas, allows this procedure to produce images of enhanced quality relative to standard ultrasound.
EUS offers a distinct advantage in the investigation of the pancreas, biliary tree, stomach wall, and lymph nodes, and in the identification of tumoral formations. Moreover, the procurement of tissue samples for subsequent biopsy is feasible during the procedure when deemed necessary. This technique offers considerable value in both diagnostic applications and the performance of selected therapeutic interventions.
What Can Endoscopic Ultrasonography Detect?
Endoscopic ultrasonography (EUS) serves as a diagnostic modality for identifying a spectrum of diseases affecting the digestive tract. Notably, it offers superior accuracy in detecting minute bile duct stones that may be imperceptible via magnetic resonance imaging (MRI). It is commonly utilized for the detection and management of the subsequent conditions:
Pancreas conditions: It exhibits significant effectiveness in identifying pancreatic cysts and masses, as well as in the diagnosis of pancreatitis and pancreatic cancer.
Biliary tract and gallbladder conditions: It is utilized for the detection of gallstones, obstructions within the biliary tract, and the presence of tumors.
Tumors of the stomach and esophagus: It can help stage gastric and esophageal cancers, and evaluate any masses detected in these locations.
Swollen lymph nodes: It is useful for examining the structural characteristics and the presence of metastasis in abdominal lymph nodes.
Conditions of the small and large intestinal walls: It is utilized for the detection of tumors and submucosal (situated below the bowel wall) growth.
Rectum cancer: It facilitates the evaluation of the degree of tumor invasion, and its resultant effects on nearby organs.
Finding the cause of the pain: It is used to find he cause of symptoms such as abdominal or chest pain.
EUS is utilized to obtain tissue specimens for biopsy, a practice that is integral to the diagnostic determination of tissues exhibiting suspicious features.
What are the Pros and Cons of Endoscopic Ultrasonography Compared to Other Methods?
- This technique allows for the precise diagnosis of pancreatic, gallbladder, and biliary tract disorders. Moreover, it enables the detection of subtle lesions undetectable by alternative imaging methods.
- It is more effective than other approaches in the detection of benign or malignant diseases of the esophagus, stomach, and intestines when these originate from their lining.
- This technique serves both diagnostic and, in certain instances, therapeutic ends. Notably, challenging therapeutic procedures, including the reliable acquisition of tissue samples for biopsy, tumor therapy, pain management through nerve blockade, and the drainage of pancreatic pseudocysts, are rendered more accessible and effective with EUS.
- It finds application in the therapeutic management of gallstones and biliary tumors, particularly in cases where standard endoscopic approaches cannot provide access to the biliary system.
- It allows for the local staging of almost all tumors of the gastrointestinal system.
What Happens Before the EUS Procedure?
Patients are required to fast before the procedure. If rectal access will be required for the procedure, a simplified bowel preparation is generally considered sufficient. Patient comfort is facilitated during this procedure through the administration of mild sedation.
What Happens During an EUS Procedure?
A healthcare provider inserts a thin tube in the patient’s mouth and throat, and then slides the ultrasound endoscope down into the stomach and small intestine through the tube. The doctor views regular images of the patient’s digestive system on one monitor, and ultrasound images on a second one. When the doctor notices any unusual tissue, he/she uses the small clamp on the scope to guide a needle biopsy. Once the doctor has a definite diagnosis, he/she can provide the required treatment.
What Happens After an EUS Procedure?
An endoscopic ultrasound procedure typically takes about 30 to 90 minutes, depending on what needs to be done. Following the procedure, patients are monitored for about 1 to 2 hours. As long as there are no issues, they can go home on the same day.