By Dr. Ramanujan Samavedy, Gastroenterologist

A technology you may not be aware of is endoscopic ultrasound. Physicians are utilizing this technology more and more to aid in gastrointestinal diseases and lung diseases assessments. Images of the digestive tract and surrounding areas by using an endoscopic ultrasound (EUS) are more accurate and detailed than traditional ultrasound and provide an experienced gastroenterologist with specialty training a more detailed look at certain diseases with a non-surgical approach.

What is Endoscopic Ultrasound?

Endoscopic Ultrasound (EUS) combines endoscopy and ultrasound in order to obtain images and information about the digestive tract and the surrounding tissue and organs. Endoscopy refers to the procedure of inserting a long flexible tube via the mouth or the rectum to visualize the digestive tract (for further information, please visit the colonoscopy and Flexible Sigmoidoscopy articles), whereas ultrasound uses high-frequency sound waves to produce images of the organs and structures inside the body such as ovaries, uterus, liver, gallbladder, pancreas, aorta, etc.

Traditional ultrasound sends sound waves to the organ(s) and back with a transducer placed on the skin overlying the organ(s) of interest. Images obtained by traditional ultrasound are not always of high quality. In EUS a small ultrasound transducer is installed on the tip of the endoscope. By inserting the endoscope into the upper or the lower digestive tract one can obtain high quality ultrasound images of the organs inside the body.

Placing the transducer on the tip of an endoscope allows the transducer to get close to the organs inside the body. Because of the proximity of the EUS transducer to the organ(s) of interest, the images obtained are frequently more accurate and more detailed than the ones obtained by traditional ultrasound. The EUS also can obtain information about the layers of the intestinal wall as well as adjacent areas such as lymph nodes and the blood vessels.

When is EUS useful?

Being a relatively new diagnostic tool the uses for EUS are still being developed and, presently, it is being utilized in some of the following situations.

• Staging of cancers of the esophagus, stomach, pancreas and rectum.
• Staging of lung cancer.
• Evaluating chronic pancreatitis and other masses or cysts of the pancreas.
• Studying bile duct abnormalities including stones in the bile duct or gallbladder, or bile duct, gallbladder, or liver tumors.
• Studying the muscles of the lower rectum and anal canal in evaluating reasons for fecal incontinence.
• Studying 'submucosal lesions' such as nodules or 'bumps' that may be hiding in the intestinal wall covered by normal appearing lining of the intestinal tract.

Staging of cancer is becoming an important use of EUS. The prognosis of a cancer victim is related to the stage of the cancer at the time of cancer detection. For example, early stage colon cancer refers to cancer confined to the inner surface of the colon before it is spread to adjacent tissues or distant organs. Therefore early stage colon cancer can be completely re-sected with good chances for cure. However, if cancer is detected at later stages, the cancer tissues have already penetrated the colon wall and invaded neighboring organs and lymph nodes, or have spread to distant organs such as liver and lungs. Complete surgical excision becomes highly unlikely. EUS can provide information regarding the depth of penetration of the cancer and spread of cancer to adjacent tissues and lymph nodes, information useful for staging.

Speak to your doctor about endoscopic ultrasound and find out if the procedure is right for you or call 865.305.6570 to find a gastroenterologist.

Click here to find out more about endoscopic ultrasound.

About the Author
Dr. Ramanujan Samavedy is the first fellowship trained endoscopic ultrasound gastroenterologist in the Knoxville region. He joined University Gastroenterology and The University of Tennessee Medical Center in 2008 from his fellowship training in Milwaukee, Wis. His special skills in gastroenterology, including endoscopic ultrasound and pancreato-biliary endoscopy, allow patients to obtain diagnostic procedures and treatments not previously available in the region. Dr. Samavedy may be reached at University Gastroenterology P.C. at 865.305.6570.