Endoscopic Ultrasound (EUS)

Endoscopic ultrasound (EUS) is a medical procedure that combines endoscopy and ultrasound to obtain images and information about the digestive tract and its surrounding tissues and organs.

What is EUS used for?

• Diagnosing diseases of the esophagus, stomach, duodenum, and rectum
• Evaluating the extent of cancer spread in the digestive tract
• Guiding fine-needle aspiration (FNA) biopsies to collect tissue samples for diagnosis
• Assessing the depth of tumor invasion and lymph node involvement
• Monitoring the response to treatment, such as chemotherapy or radiation therapy

How is EUS performed?

EUS is typically performed on an outpatient basis, and the procedure usually takes 30-60 minutes. The patient is given conscious sedation to relax and reduce discomfort.

1. The patient lies on their side or back on an examination table
2. A flexible tube with a high-frequency ultrasound probe at its tip (endoscope) is inserted through the mouth or rectum, depending on the area being examined
3. The endoscope is guided to the desired location using visual and ultrasound guidance
4. Ultrasound waves are emitted from the probe, producing high-quality images of the surrounding tissues and organs
5. The images are displayed on a monitor for the doctor to interpret
6. If necessary, FNA biopsies can be performed using a thin needle guided by ultrasound

Risks and complications

While EUS is generally considered safe, there are potential risks and complications, including:

• Bleeding or perforation of the digestive tract
• Infection
• Adverse reactions to sedation or anesthesia
• Dysphagia (difficulty swallowing) or odynophagia (painful swallowing)

Preparation and aftercare

To prepare for EUS, patients should:

• Fast for at least 6 hours before the procedure
• Avoid taking anticoagulant medications or adjust their dosage as instructed by their doctor
• Inform their doctor about any allergies or medical conditions

After the procedure, patients should:

• Rest for a few hours to allow the sedation to wear off
• Avoid eating or drinking for at least 2 hours
• Follow their doctor's instructions regarding medication and activity level