The University of Arkansas for Medical Sciences (UAMS) plays a leading role in this minimally invasive advanced imaging technique and accounts for over 80 percent of its use in the region.

“It is essentially an endoscope with a maneuverable tip and a built-in digital ultrasound transducer,” said Benjamin Tharian, MD, an interventional gastroenterologist and the director of advanced endoscopy at UAMS. “EUS uses high-frequency sound waves to produce detailed images of the gastrointestinal tract and adjacent organs within proximity to the gut.

Tharian said there are innumerable advantages to using endoscopic ultrasound to both diagnose and treat illnesses.

“Endoscopic ultrasound combines traditional ultrasound techniques including doppler processes with endoscopic techniques,” Tharian said. “There is fine needle biopsy and therapeutic capacity through large channels through which instruments are passed. Higher frequencies give greater definition of tissues close to the transducer but less ability to see details further away for which lower frequencies are used.

The device which has an ultrasound probe at its tip is mostly inserted through the mouth just like a normal endoscope and rarely through the anal canal to evaluate the rectum and adjacent organs.

“With its unique ability to do an ultrasound inside out, it can be used to evaluate the mediastinum, pancreas, liver, bile ducts, the gut wall, rectum, lymph glands and any nearby organ,” Tharian said. “It has a major role in the diagnosis and staging of several cancerous conditions in the upper and lower gut. It can be used to take tissue samples and biopsies from lymph glands or liver, to evaluate pancreatic scar tissue (chronic pancreatitis), mass or cysts and tumors arising from the deeper layers of the gut, in a safe and minimally invasive manner.”

Tharian said the technique enables the decision making process of operable versus inoperable tumors with great accuracy. EUS is invaluable in expediting the management of patients with unexplained or recurrent pancreatitis to find out the cause and guide treatment. It picks up small stones (microlithiasis) that are often responsible for pancreatitis and tiny cancerous lesions missed on MRI/CT scans.

“There are a lot of therapeutic uses of endoscopic ultrasound,” Tharian said. “The therapeutic indications for EUS include coeliac plexus neurolysis for cancer pain, drainage of inflammatory/infected fluid collections, creation of enteric anastomoses to palliate obstruction from cancer and biliary access to relieve jaundice where the conventional ERCP has failed and in palliative drainage of the gallbladder when it is obstructed by tumor. The advantage of EUS over conventional techniques is the minimally invasive nature and lack of any external drains or incisions, in addition to quick recovery.”

Patients with chronic pancreatitis and advanced visceral cancers (like pancreatic) often have severe abdominal pain that does not respond to oral pain medications. Tharian said they can safely inject medications into the celiac plexus under EUS guidance and block those nerves, thus significantly alleviating the pain in a 20 minute procedure. The effect can last six to nine months. If a patient responds to it, we can repeat it once it wears off.”

Patients with severe necrotizing pancreatitis can develop pseudo cysts from fluid that leaks out, in proximity to the pancreas. “Previously, the only treatment was open surgery lasting for four hours, and patients had to stay in the hospital for up to a week,” Tharian said. “But with endoscopic ultrasound, we do the procedure in less than an hour and the patient can go home the same or next day. This procedure is effective in over 90 percent of patients, with open surgery reserved for the ones that do not respond to this minimally invasive procedure.”