Endosonography - Information & Endosonography Specialists

Endoscopic ultrasound (EUS), also known as endosonography (ultrasound from within), is a combination of endoscopy and ultrasound. An ultrasound probe is attached to the tip of the endoscope.

This probe can be guided through the endoscope directly to the area being examined, such as 

• the esophagus,
• the stomach, or
• the small intestine,

. The examination not only provides a detailed image of the walls of the gastrointestinal tract but also of neighboring organs and structures, such as

• the pancreas,
• the biliary tract,
• the adrenal glands,
• the bronchial system.

Of all the technical devices used in medicine, ultrasound has the highest resolution. For example, this method is the only one capable of visualizing the five layers of the gastrointestinal tract wall (minimum thickness 2 mm).

This is of enormous importance for determining the therapeutic approach when evaluating tumors.

Tumor diagnosis

Various medical societies have included endosonography as an essential diagnostic method in their recommendations for the diagnosis of tumors

• of the gastrointestinal tract,
• the pancreas, and
• the lungs, as well as
• the bronchi

. Endosonography can help physicians assess the extent of such tumors. This assessment is of crucial importance for subsequent cancer treatment.

Fig. 1: Endosonographic findings of a small malignant tumor confined to the first layer, which was endoscopically resected

Fig. 2: Locally advanced malignant gastric tumor with growth beyond the wall and evidence of enlarged lymph nodes. The patient received prior chemotherapy and subsequently underwent successful surgery

Physicians must determine whether the tumor is resectable—that is, whether it can be removed using an endoscopic procedure or primarily through surgery.

Alternatively, the tumor could first be reduced in size using chemotherapy or radiation therapy. This is an option primarily for larger tumors where enlarged lymph nodes are already detectable. The goal is to bring the tumor to a state that allows for curative surgery.

Pancreas and Biliary Tract Diagnostics

Another focus of endosonography is the diagnosis of the pancreas and the biliary tract. In patients with

• unexplained abdominal pain,
• colic,
• elevated liver enzyme levels, or
• dilated duct systems in the pancreas or liver for which no cause can be identified

, a diagnosis cannot always be made using conventional ultrasound or computed tomography. In these cases, endosonography can provide clarity.

It can detect even the smallest pancreatic tumors (as small as 3 mm). At this stage, this aggressive tumor is still curable.

Endosonography can also detect small gallstones or tumors in the bile duct, thereby enabling early treatment.

Fig. 3: Patient with unexplained upper abdominal symptoms and no evidence of a tumor on computed tomography (CT) or conventional ultrasound. Endosonography detected a small tumor. The patient underwent surgery and is now cured

Fig. 4: Patient with recurrent right-sided upper abdominal symptoms and normal liver function tests. Endosonography revealed a small stone in the bile duct immediately before its opening. The stone was removed endoscopically

Fig. 5: Specialized endosonography with tissue identification via elasticity measurement. Malignant tumors are displayed in blue. Here, a targeted endosonographic biopsy was performed on an enlarged lymph node—tissue examination confirmed the presence of a malignant tumor metastasis

Diagnosis of Other Unclear Findings

The repertoire of interventional endosonography also offers expanded diagnostic and therapeutic options. Through targeted punctures guided by endosonography, unclear findings

• in the pancreas or
• in the wall of the gastrointestinal tract
• as well as unclear enlarged lymph nodes

can be investigated.

The cellular material obtained with the puncture needle is examined under a microscope. This allows for a diagnostic classification of the findings in nearly 90–95% of cases. These findings significantly facilitate therapeutic decision-making and may, under certain circumstances, prevent the need for surgery.

Endosonography also allows for the aspiration of regions that are inaccessible from the outside or can only be reached at high risk. These include

• areas within the chest cavity,
• regions rich in blood vessels,
• and the adrenal glands.

The safe application of the puncture technique has paved the way for endosonographic therapy. Patients with acute or chronic inflammation of the pancreas can be treated using endosonography. They often develop a painful collection of fluid, which may also be infected, 

In such cases, an internal drainage of the fluid collection into the stomach or small intestine is established. This allows these patients to avoid surgery.

Fig. 6: Patient with pain due to the formation of a cyst following inflammation of the pancreas. Endosonographic puncture of the cyst and creation of an internal drainage channel from the cyst into the stomach

Newer therapeutic approaches include the internal drainage of a obstructed biliary tract in patients with incurable tumors

• of the pancreas.
• the stomach, or
• the bile ducts,

in whom endoscopic internal drainage cannot be achieved.

Fig. 7: Patient with jaundice due to impaired bile flow resulting from a malignant tumor of the pancreas. Bile flow into the small intestine is obstructed due to a narrowing caused by the tumor and the prosthesis located in the small intestine. Relief of the bile ducts is achieved by creating a new internal drainage channel into the small intestine

These patients can be spared a painful external bile drainage that impairs their quality of life for the rest of their lives.

An endosonography is usually performed on an outpatient basis if it is a diagnostic procedure without a tissue sample.

In most cases, endosonographic punctures require one day of inpatient monitoring. If internal drainage of fluids, cysts, or inflammatory foci is planned, these procedures are performed during an inpatient stay.

Prerequisites for an endosonography include the patient’s informed consent following a consultation and the availability of current blood coagulation test results. The procedure is similar to a gastroscopy. The endoscope, which has a transducer at its tip, has a diameter of approximately 1 cm and is inserted into the esophagus under direct visualization.

An endosonography is completely painless. Like a gastroscopy or colonoscopy, it is usually performed under anesthesia. During the procedure, the patient’s vital signs (blood pressure, pulse, and blood oxygen levels) are monitored.

Depending on the purpose, the procedure lasts between 5 minutes (diagnostic) and 45 minutes (therapeutic). If the endosonography was performed with sedatives, a 1–2-hour observation period is required. During this time, the patient is connected to a monitoring system.

The results are discussed and the patient is discharged once they have regained full consciousness. Even if patients appear to be feeling well again, they are still unfit to drive for the remainder of the day. It is therefore advisable for patients to arrange for someone to pick them up.

Serious complications are rare with endosonography and usually occur only after punctures or therapeutic procedures. These complications include bleeding or infections.

In rare cases, difficulty swallowing may occur for 1–2 days following a diagnostic endosonography.