EUS: A Procedure With Multiple Indications

Endoscopic ultrasound, or EUS, can help stage several types of cancers.Chun Hsu, MD North Kansas City Hospital gastroenterologist Chun Hsu, MD calls it the “gold standard” in evaluating the pancreas.

But Dr. Hsu says doctors aren’t always aware of all the roles EUS can play. While a valuable diagnostic and staging tool for pancreatic tumors, it can also be used to evaluate other organs, for biopsies and even to inject nerve blockers.

“It’s such a specialized procedure within a specialized field,” says Hsu, who counsels patients at his practice, Consultants in Gastroenterology, and performs EUS at the Hospital.

While Dr. Hsu receives most of his EUS requests from other specialists like oncologists, pulmonologists and fellow GIs, there are also appropriate opportunities for PCPs to make referrals. Since time is of the essence in many cases, referrals can mean identifying disease before it worsens, especially in the pancreas. “It’s always better to evaluate cases early,” Dr. Hsu says.

EUS: A Versatile Procedure

Dr. Hsu has been performing EUS for more than three years, averaging eight procedures per week. He received his GI training at the University of Michigan, and has completed over 1,000 EUS procedures — more than the 250 cases recommended by the American Society for Gastrointestinal Endoscopy. Dr. Hsu is among a handful of metro-wide GIs performing EUS and the only one north of the river.

As with a standard endoscope, he uses a camera for positioning during EUS and can examine either the upper or lower gastrointestinal tracts. The scope is fitted with a miniature ultrasound probe – a useful tool because disease can reside in multiple layers in the GI tract and not just on the easily visible mucosa, Dr. Hsu says.

The procedure can also look at nearby organs — the liver, gall bladder, pancreas, spleen, and lungs — and evaluate lymph nodes and masses in the mediastinum, abdomen and rectum.

EUS can substitute for needle biopsies of lymph nodes and masses in the abdomen and mediastinum, for example. And the procedure is used to stage rectal and esophageal cancers once metastasis is ruled out, though it’s not as effective if treatment has already begun – a frequent problem, Dr. Hsu says. “By then it’s very difficult to do,” he says, as differences between tumor and inflamed or scarred tissue become muddled.

In some cases, Dr. Hsu can also use EUS to inject a nerve blocker into the celiac plexus for relief of severe pain caused by pancreatic cancer or chronic pancreatitis. 

EUS: What To Expect

EUS referrals from PCPs usually come after abnormalities are spotted on CT scans, Hsu says. He estimates his case breakdown as follows: 70 percent for the pancreas, 20 percent for the stomach and esophagus, and 10 percent for other areas.

Hsu says EUS referrals can be made before a CT scan for alarming symptoms such as unintended weight loss, persistent diarrhea, decreased appetite or abdominal pain radiating to the back.

Hsu first meets patients in his office to determine a course of action, potentially including “careful watching.” In certain cases, an EGD will be scheduled for the same time as EUS, so the patient is sedated only once.

When EUS is requested, patients are usually seen within a week. Referrals go through an expedited channel and should be marked “EUS.” Immediately following a EUS procedure, a dictated report including findings and recommendations will be sent to the referring physician(s).

Chun Hsu, MD

Dr. Hsu received his MD from Tufts University School of Medicine in Boston, completed a residency in internal medicine at McGaw Medical Center of Northwestern University in Chicago and a gastroenterology fellowship at the University of Michigan Hospitals in Ann Arbor. He has performed EUS for more than three years and completed over 1,000 EUS procedures.

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