Endoscopic Laboratory

ERCP is performed by specialized interventional endoscopists in the presence of an anesthesiologist within the Clinic's dedicated fluoroscopy suite. Metropolitan General is equipped with a latest-generation, fully digital, remote-controlled fluoroscopy system with a flat panel detector, providing optimal image quality and high resolution at the lowest possible radiation dose.

• Diagnostic ERCP: (Though Endoscopic Ultrasound (EUS) and Magnetic Resonance Cholangiopancreatography (MRCP) are preferred for their superior safety profile and accuracy)
• Interventional ERCP: (Sphincterotomy, stone removal, lithotripsy, placement of plastic and self-expanding metal stents, and drainage placement)

What is Endoscopic Ultrasound?

Endoscopic Ultrasound (EUS) is an innovative procedure that combines endoscopy with ultrasound. It is performed using specialized endoscopes equipped with a small ultrasound transducer at the tip. During an endoscopy of the upper or lower gastrointestinal tract, the ultrasound allows us to see beyond the walls of the gastrointestinal lumen. Consequently, we can study in detail both the structure of the gastrointestinal wall and the adjacent tissues and organs, such as the pancreas, liver, spleen, biliary tract, lymph nodes, and blood vessels.

State-of-the-Art EUS System

Metropolitan General houses the most advanced EUS system in Greece, combining the latest generation Pentax EUS-J10 ultrasound endoscope with the Hitachi Arietta V60 ultrasound processor.

• The Pentax EUS-J10 is designed for enhanced maneuverability, precision, and safety, improving diagnostic and therapeutic efficacy.
• Its ergonomic design ensures stability and ease of intubation, while the Pentax-Hitachi image quality provides unparalleled visualization.
• The system supports Contrast-Enhanced EUS (CE-EUS) for greater diagnostic precision and third-generation Elastography to evaluate tissue stiffness.

Where does this method excel?

The ability to position the ultrasound probe remarkably close to the organs and tissues being examined provides images of exceptionally high resolution.

As a result, Endoscopic Ultrasound (EUS) can clarify and characterize findings detected by other imaging examinations, such as CT or MRI, with a high degree of accuracy. In many cases, it can also detect exceedingly small lesions, only a few millimeters in size, which may not be visible with conventional imaging methods.

Needle Biopsies

Using EUS, we can obtain samples from tissues, cysts, or solid masses via a fine needle under real-time ultrasound guidance. This material is then examined for a definitive diagnosis. This procedure, known as Fine Needle Aspiration (FNA) or Fine Needle Biopsy (FNB), is less invasive and safer compared to alternative methods.

Cutting-Edge Technology: Elastography

Certain conditions, such as cancer, are known to increase tissue stiffness. The advanced Endoscopic Ultrasound (EUS) system at Metropolitan General features Elastography, an innovative technique that enables assessment of the stiffness of the tissues being examined. This provides additional diagnostic information that may support clinical diagnosis.

With the aid of Elastography, the biopsy needle can be guided to the firmest area of the lesion under evaluation, thereby maximizing the likelihood of a successful diagnostic procedure.

In addition, the Department’s equipment allows the use of intravenous microbubbles as contrast agents, which facilitate the characterization and detection of suspicious lesions that may not be visible with conventional imaging methods.

How is Endoscopic Ultrasound (EUS) performed?

Endoscopic Ultrasound (EUS) is performed in most cases under sedation, ensuring a comfortable experience for the patient and painless biopsy procedure. Most patients can return home on the same day after the examination, and results may be available immediately. If a biopsy has been taken, results are regularly available within a few days, following completion of the cytological or histological analysis.

Clinical Applications

Diagnostic

• Diagnosis and staging of esophageal, gastric, pancreatic, and rectal cancers
• Staging of lung cancer
• Evaluation of chronic pancreatitis
• Assessment of pancreatic masses and cysts
• Evaluation of biliary diseases, such as gallstones or tumors of the gallbladder, bile ducts, or liver
• Assessment of the anal sphincters in the investigation of fecal incontinence
• Evaluation of subepithelial tumors of the gastrointestinal tract
• Evaluation of enlarged lymph nodes

Therapeutic

• Drainage of cysts and abscesses
• Drainage of pancreatic necrotic collections and pseudocysts
• Placement of fiducial markers for image-guided radiotherapy
• Celiac plexus neurolysis for palliative pain management in cases of inoperable pancreatic cancer

Endoscopic Ultrasound Department Physician in Charge: Panagiotakopoulos, Dimitrios, Gastroenterologist

What is the ESD technique?

Endoscopic Submucosal Dissection (ESD) is an innovative interventional endoscopic technique that originated in Japan and has been supported by more than 20 years of clinical experience.

ESD represents the latest advancement in therapeutic endoscopy, allowing en bloc resection (removal in a single piece) of larger and histologically advanced epithelial lesions. These include early-stage cancers of the upper and lower gastrointestinal tract, such as the esophagus, stomach, and colon, as well as a wide range of mucosal lesions that previously required surgical removal.

With the ESD technique, the affected area of the gastrointestinal tract is removed with high precision, while the muscular layer of the organ remains intact, helping to avoid surgical resection of the affected organ.

Which gastrointestinal lesions can be treated with ESD?

The wall of the gastrointestinal tract (the esophagus, stomach, and colon) consists of several layers. From the inside outward, these include the mucosa, the submucosal layer, the muscular layer, and the serosa.

All gastrointestinal lesions initially develop in the mucosa. In the colon, they often form what is known as a polyp, while in the esophagus and stomach early lesions are usually not clearly distinguishable. Dysplastic changes may then develop in the mucosal cells, ranging from low-grade to high-grade dysplasia.

These dysplastic lesions may subsequently extend beyond the mucosa into deeper layers of the gastrointestinal wall, such as the submucosal layer. At this stage, malignant invasive transformation may begin and can progress either into the muscular layer of the organ or, through the vessels of the submucosal layer, beyond the gastrointestinal wall to the regional lymph nodes.

ESD can be performed when an early lesion is confined to the mucosa or the upper layers of the submucosa (stages T1a and T1b1). Endoscopic removal of such lesions is feasible and oncologically adequate when the malignant lesion has not extended into the deeper layers of the submucosa, namely stage T1b2.

To determine whether a lesion can be removed endoscopically, it must be carefully assessed using high-definition magnifying endoscopy, chromoendoscopy, and/or endoscopic ultrasound (EUS).

Latest-generation video-endoscopy systems feature Image Enhanced Endoscopy – IEE/ME-NBI technology, meaning Image Enhanced Endoscopy and Magnification Narrow Band Imaging. These technologies enable the early diagnosis of malignant lesions in the esophagus, stomach, and colon at an incredibly early stage during gastroscopy or colonoscopy.

In practice, endoscopic visualization can provide an “optical biopsy” of a lesion at up to 85x magnification. This allows the endoscopist to identify the nature of the lesion, obtain a targeted biopsy, or proceed with endoscopic resection using the ESD technique, achieving healthy lateral and vertical margins by dissecting the lesion at a deeper level.

How have these lesions been treated until now?

Until recently, when a lesion was detected during endoscopy, the usual approach involved taking an endoscopic biopsy and, depending on the result, scheduling a second procedure for endoscopic removal using a diathermy snare in one or more fragments (known as piecemeal EMR) or proceeding with surgical removal of part or all of the affected organ.

Waiting for the biopsy result, together with the possible development of fibrosis in the gastrointestinal wall, often made subsequent endoscopic treatment difficult and less effective, particularly in lesions of the colon.

Even when endoscopic removal was performed, pathological tissue could remain in the organ, or the lesion could extend into a deeper layer, leading to recurrence in 21–46% of cases. As a result, patients often require repeated endoscopic resections or open surgery.

How effective is ESD?

The ESD technique offers:

• Definitive removal of malignant lesions in 95% of gastric cases and 92.5% of colonic cases
• Almost zero recurrence rates, ranging from 0% to 1% of cases

The oncological principle of ESD allows accurate histopathological staging and analysis of malignant tissue, as the lesion is removed in a single piece with the maximum deep margin. This provides the safest basis for future follow-up in cases of R0 resection or enables clear indications to be proved for oncological surgery in cases of massive deep invasion of the submucosal layer (T1b2 stage).

ESD vs EMR (conventional Endoscopic Mucosal Resection)

Compared with conventional Endoscopic Mucosal Resection (EMR), which is used for superficial colonic polyps, ESD is superior regardless of the size and location of the lesion.

It achieves higher rates of:

• Successful en bloc resection: 95% vs 58%
  
• Curative R0 resection: 89% vs 22%
  
• Lower local recurrence: 0,3% vs 25%

Based on these outcomes, ESD is clinically more effective than EMR and minimally invasive compared with surgical treatment. Although ESD is associated with bleeding and perforation rates of 9% and 4.5%, respectively (compared with 5.8% and 1% for EMR), these complications are effectively managed during the procedure, without clinical consequences.

Since 2015, the European Society of Gastrointestinal Endoscopy (ESGE) has recommended that all early lesions of the stomach and esophagus be removed using ESD. For the colon, ESD is recommended for specific types of polyps and for almost all rectal polyps larger than 2.5 cm.

How is ESD performed?

ESD is an endoscopic-surgical technique performed with the use of an endoscope, which is introduced through the mouth or the rectum, depending on the location of the tumor (esophagus, stomach, or colon). Throughout the procedure, the patient is watched by an anesthesiologist for the administration of sedation.

The procedure includes the following steps:

• Marking the area around the lesion within healthy margins using thermal coagulation, under direct visualization with a High-Definition endoscope, following lesion delineation with chromoendoscopy
• Injection of a special solution into the submucosal layer using a sclerotherapy needle
• Complete circumferential mucosal incision using a specialized electrosurgical knife
• Dissection along the mucosal–submucosal interface
• Complete dissection across the full width and length of the submucosal layer, followed by en bloc resection of the neoplasm
• Inspection of the artificial ulcer and prophylactic hemostasis of visible vessels on the muscular layer
• Fixation of the lesion on a special cork board and preparation for histological examination

For ESD to be performed safely, it is essential that the endoscopist has been trained in a highly experienced center, mainly in Asia or selected European centers, as this is a particularly demanding technique.

Equally important is the availability of proper latest-generation endoscopic equipment, offering high-resolution image enhancement and advanced interventional capabilities.

Advanced endoscopic procedures such as ESD are performed in a specialized endoscopy unit, with the primary goal of ensuring maximum safety and effectiveness for the patient.

Metropolitan General is one of the few medical centers internationally where this technique is performed, by Dr. Bassioukas Stefanos, Gastroenterologist-Interventional Endoscopist, Director of the Advanced Therapeutic Endoscopy Gastroenterology Clinic.

Metropolitan General is equipped with state-of-the-art medical technology used exclusively for interventional pulmonology procedures.

The endoscopic tower, at the forefront of interventional pulmonology, features high-definition video endoscopes and advanced imaging techniques, including Narrow Band Imaging (NBI).

It is equipped with the latest processors (EVIS EXERA III / CV-190plus and EVIS EUS EU-ME2) providing excellent brightness, best visualization, and high-definition ultrasound imaging, supported by modern technologies for the recognition and identification of the structures being examined.

The Laboratory’s bronchoscopes include the latest-generation BF1TH1100 bronchoscope, the MAJ 1720 radial EBUS system for peripheral ultrasound, and the BF-UC190F Convex Probe EBUS (CP-EBUS) system for central endobronchial ultrasound.

Diagnostic techniques performed include:

• Flexible video-bronchoscopy
  An endoscopic examination performed with a flexible bronchoscope — a thin, advanced tube with flexible optical fibers and light fibers that send images from inside the bronchi to the physician’s monitor. At the
  Bronchoscopy Laboratory of Metropolitan General, video-bronchoscopy is performed with collection of bronchial and transbronchial biopsies, bronchoalveolar lavage (BAL), bronchial secretions for cultures, and samples required for molecular and cytological testing
• Convex Probe Endobronchial Ultrasound (CP-EBUS)
  Used for sampling mediastinal and hilar lymph nodes, as well as central lesions.
• Radial probe EBUS bronchoscopy
  Used for the approach and assessment of peripheral lesions.
• NBI bronchoscopy
  Used for the detection of early dysplastic or malignant lesions with the aid of Narrow Band Imaging
  
• Bronchoscopy with ablative techniques
  Including argon plasma coagulation and electrocautery, used for the opening of central airways and for hemostasis

A valuable tool of the Bronchoscopy Department at Metropolitan General is Convex Probe Endobronchial Ultrasound (CP-EBUS).

CP-EBUS is an examination that allows the pulmonologist to evaluate the lungs and surrounding structures in greater detail. It is used for the diagnosis of different respiratory diseases, including neoplasms, infections, and other inflammatory conditions. The procedure is similar to bronchoscopy.

How is it performed?

The examination is performed using a flexible bronchoscope, which is introduced through the mouth, then into the trachea and finally into the lungs.

The bronchoscope has a video camera and an ultrasound probe at its tip, allowing visualization and direct sampling of lymph nodes or lesions located centrally in the chest or around the lungs, outside the bronchi.

It enables the detection of even small lesions and helps distinguish them from adjacent blood vessels, allowing biopsy with a special needle under direct visualization.

Safety and diagnostic accuracy

CP-EBUS is a particularly safe examination, as samples are obtained under direct real-time guidance. This not only enhances safety but also ensures high diagnostic accuracy.

This technique has exceedingly high sensitivity and specificity in the diagnosis of mediastinal lesions. Since it usually does not require hospitalization or surgery, it now plays a significant role in the diagnosis and staging of lung cancer before surgical resection, radiotherapy, or chemo-immunotherapy.

By enabling the collection of not only cytological but also biopsy material from mediastinal lymph nodes, CP-EBUS also contributes significantly to the diagnosis of benign granulomatous or infectious diseases, such as sarcoidosis and tuberculosis.

Innovative equipment

At Metropolitan General, a latest-generation endoscopic ultrasound system is used, featuring the EVIS EUS EU-ME2 ultrasound processor and the BF-UC190F ultrasound bronchoscope.

This state-of-the-art, third-generation EBUS system has been developed to ensure easy passage through the upper airway, optimal ultrasound and endoscopic imaging, maximum control, and flexibility for easier access to the required sites, supporting diagnosis and staging even in distant lesions.

The Laboratory also offers Rapid On-Site Evaluation (ROSE) of cytological material during the examination, further enhancing diagnostic accuracy.

Contact Number: +30 210 650 2624