Sometimes gastrointestinal disorders are not only on the “inner surface” seen by conventional endoscopy but may be hidden deep beneath the organ wall layers or located in the pancreas, bile ducts, and nearby lymph nodes.
What is EUS?
Endoscopic Ultrasound or EUS is a technology that combines gastrointestinal endoscopy with high-frequency ultrasound waves in a single device, allowing doctors to evaluate both the inner surface and deep structures in real-time during one examination.
When is EUS commonly used?
1. Evaluation of masses in the gastrointestinal system
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- Submucosal tumors
- Masses in the esophagus, stomach, intestines
- Differentiation of mass types such as cysts, tumors, or cancer
2. Evaluation of pancreatic and bile duct diseases
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- Suspected pancreatic cancer
- Pancreatic cystic diseases
- Bile duct stones
- Bile duct strictures
3. Cancer staging EUS helps assess the depth of tumor invasion and lymph node spread, which affects treatment planning such as surgery, chemotherapy, or targeted therapy.
4. Accurate tissue biopsy (EUS-FNA / FNB) A small needle can be used to aspirate cells or tissue from deep masses that are normally inaccessible without open surgery, improving diagnostic accuracy.
5. Non-surgical treatment of bile duct and pancreatic diseases such as pancreatic pseudocysts, bile duct or pancreatic cancer with obstruction, and cholecystitis in patients who prefer not to undergo surgery.
How is EUS different from conventional endoscopy?
| Conventional Endoscopy | EUS |
| Sees only the inner surface | Sees deep wall layers and surrounding structures |
| Cannot see deep lymph nodes | Can evaluate lymph nodes and blood vessels |
| Cannot biopsy deep masses | Can accurately biopsy (EUS-FNA/FNB) |
EUS procedure steps
- Before the exam, fast from food and water for 6–8 hours. Inform the doctor if you have any chronic diseases or are taking blood thinners. It is advisable to have a companion as you may feel drowsy after the procedure.
- During the exam, you will receive short-acting sedation to reduce discomfort. The doctor will insert the endoscope through the mouth (or anus in some cases). The procedure takes about 30–60 minutes. If a mass is found, the doctor may perform a biopsy during the same session.
- After the exam, rest and be observed for 1–2 hours. You may experience a sore throat or mild abdominal discomfort, which usually resolves on its own. If you have severe abdominal pain, high fever, vomiting blood, or black stools, seek medical attention immediately.
Is EUS safe?
Generally, EUS is a very safe procedure with few complications such as bleeding or infection (especially in biopsy cases). Doctors will assess indications, necessity, and individual risks before every examination to ensure maximum safety.
Who should consider EUS?
If you have any of the following symptoms, you should consult a gastrointestinal specialist:
- Chronic unexplained abdominal pain
- Unexplained weight loss
- Jaundice, yellowing of skin and eyes
- Abnormal masses or cysts found on CT or MRI, especially in the pancreas and bile ducts
- Submucosal masses found on conventional endoscopy
Advantages of EUS
- Provides deeper detail than conventional endoscopy and additional information beyond CT or MRI
- Reduces the need for diagnostic surgery
- Allows accurate tissue biopsy
- Enables precise treatment planning
- Increases the chance of detecting diseases at an early stage
Care by a specialized medical team at Phyathai 2 Hospital
EUS examinations at Phyathai 2 Hospital are performed by gastrointestinal endoscopy specialists under strict infection control standards in the endoscopy suite.
An anesthesiology team manages sedation and works collaboratively with a multidisciplinary team including surgeons, oncologists, and radiologists to provide comprehensive treatment planning. Our approach emphasizes
- Comprehensive evaluation
- Clear explanation to patients
- Selection of individualized treatment plans
- Safety as a top priority
Because accurate diagnosis is the starting point for appropriate treatment
If you have chronic abdominal pain, unexplained weight loss, jaundice, or abnormal masses or cysts found on imaging, especially in the bile ducts and pancreas, EUS evaluation may be an important step to help doctors plan targeted treatment from the early stages.
At Phyathai 2 Hospital, we are ready to care for you with a specialized medical team, advanced technology, and a holistic treatment approach to ensure every diagnosis leads to appropriate, safe, and confident care at every step.
Dr. Kittithat Tantithanawat
Specialist in Advanced Gastrointestinal Endoscopy
Phyathai 2 Hospital
