Ultrasound is an internal abdominal examination technology that helps doctors see abnormalities occurring within the digestive tract. However, ultrasound has limitations in that it can only visualize internal abdominal organs and surrounding organs. It cannot clearly see organs located deeper behind the stomach, such as the pancreas or the biliary system. Currently, a new ultrasound technology called Endoscopic Ultrasound (EUS) has been developed, allowing doctors to examine the digestive system more clearly and in greater depth.
What is an EUS ultrasound examination?
Endoscopic Ultrasound (EUS) is an examination of the digestive system using an endoscope equipped with ultrasound. This method allows doctors to see the mucosal lining and walls of the digestive tract, from the upper parts including the esophagus, stomach, and duodenum, to the lower digestive tract walls including the colon and rectum. It is also used to examine internal organs near the digestive system that external ultrasound cannot reach, such as the gallbladder and liver.
How does the EUS procedure work?
Doctors use a small tube-shaped endoscope with a flexible curved tip, inserted through the mouth or anus, then moved to the desired examination site. The ultrasound machine is then activated to generate sound waves and create images of the digestive system.
Benefits of EUS
- Diagnostic purposes
- Detect gallstones in the bile duct without ERCP
In the case of detecting gallstones in the bile duct, in the past, if doctors suspected a patient had gallstones, they had to perform Endoscopic Retrograde Cholangiopancreatography (ERCP), a complex procedure with several risks such as intestinal perforation, bleeding from the bile duct, and pancreatitis. Therefore, if doctors want to diagnose gallstones in the bile duct, they can use EUS instead, which also reduces the risks associated with ERCP.
- Biopsy can be performed without causing pain to the patient
When a biopsy is needed to diagnose pancreatic cancer or abnormalities in lymph nodes, EUS can be used to perform ultrasound through the abdomen instead of X-rays from the back, allowing doctors to see the target organs with higher resolution. If a biopsy is required, EUS can be equipped with tools to collect tissue samples for further examination, enabling patients to receive a more detailed diagnosis in a single procedure without any risk.
- Treatment purposes
- Treat bile duct obstruction without the need for an external drainage bag
In cases where patients have bile duct obstruction due to cancer or bile duct stricture causing jaundice, doctors need to treat by draining the bile duct to restore normal function. Traditional treatment requires patients to carry an external drainage bag permanently. Nowadays, EUS is used for bile duct treatment by attaching equipment to the ultrasound endoscope, allowing doctors to create a new drainage pathway for bile flow. Although this method carries higher risks and costs more than ERCP, it can help patients recover from jaundice without needing a permanent external drainage bag.
Dr. Warayu Prachyakul
Specialist in Gastrointestinal Endoscopy
Gastrointestinal and Liver Center
Phyathai 2 Hospital, 4th Floor, Building A
Tel. 02-617-2444 ext. 7401, 7406
