Using the Endoscope for Endobronchial Ultrasound in the Esophagus
November 21st, 2023
Transesophageal ultrasound (EUS-B) is a safe and feasible procedure using the echoendobronchoscope (EBUS) in esophagus and stomach. After identifying six anatomical landmarks, additional structures can be identified and biopsied, sparing subsequent diagnostic sessions. Thus, EUS-B is an ideal continuation of bronchoscopy and EBUS in diagnosing lung cancer and other diseases.
Our scope is to identify new ways to perform biopsies from otherwise difficult-to-access areas in the most patient-friendly way, thus conclusive biopsies with few adverse events, low patients'discomfort, and low costs. EUS-B is a safe technique in the hands of respiratory physicians, despite that biopsies are taken not from the lungs or airways, but from the esophagus or stomach. It allows for more complete investigation of patients with possible lung cancer or other cancer.
We have contributed significantly to the field by exploring utility and safety of EUS-B, including identification of new targets that can be reached and sampled. The aspect of patient safety is of outmost importance, and EUS-B has no serious complications. EUS-B is an emerging technique, and there are still no simulators or phantoms that allows for safe learning of the technique.
This protocol provides a clear and stepwise instruction to support beginners and mentors to improve the learning curve. To begin, position the patient in a supine and apply monitoring equipment. Continuously monitor three-lead telemetry, oxygen saturation, pulse, and intermittent blood pressure.
While standing behind the patient's head, hold the handle of the echo endo bronchoscope with the left hand, thumb in the lever, and distal end in the right hand. Apply local anesthetic gel on the tip of the endoscope, then orally or through the nostril, introduce the endoscope into the oropharynx of the anesthetized patient. Advance the endoscope into the laryngeal pharynx while the epiglottis is in front of the scope.
Visualize the vocal cords using the bronchoscopic view. Next, turn the scope left or right to direct it lateral to the arytenoids. Ask the patient to swallow and slowly bend the endoscope posteriorly, introducing it into the esophagus following the patient's swallowing movement.
If required, spray two milliliters of topical lidocaine in the oropharynx. To identify six endoscopic ultrasound landmarks, shift to the ultrasonic image and introduce the endoscope into the stomach. At landmark one, turn the endoscope slightly counterclockwise to visualize the left liver lobe.
At landmark two, turn the scope clockwise to visualize the abdominal aorta with the celiac trunk and superior mesenteric artery. Turn the scope further clockwise at landmark three to visualize the left adrenal gland. At landmark four, retract the endoscope to the mediastinum to locate the mediastinal lymph node station seven.
Next, retract the endoscope a few centimeters and observe the reflections from the trachea. Now turn the endoscope counterclockwise, and at landmark five, find mediastinal lymph node station 4L between the aortic arch and the left pulmonary artery. At landmark six, turn the endoscope clockwise and pass the trachea to find the azygos vein and mediastinal lymph node station 4R.
Insert the sheath in the endoscope and adjust the length such that the tip is one millimeter outside the endoscope. Then lock the sheath in place. Move the FNA needle with the stylet forward and retract the stylet a few millimeters to sharpen the needle.
Under real-time ultra sonographic guidance, hit the target lesions, then retract the stylet and apply suction to the needle. Move the needle back and forth. Remove the suction and lock the needle in the upper position before removing the equipment from the endoscope.
The transesophageal ultrasound tissue sampling technique shows that diagnostic hit rates vary according to location, with slightly higher diagnostic success rates of intrathoracic lesions.
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Overview
Transesophageal ultrasound (EUS-B) is a safe and effective procedure that allows for biopsies from the esophagus and stomach, aiding in the diagnosis of lung cancer and other diseases. This technique enhances patient safety and comfort while minimizing complications.
Key Study Components
Area of Science
- Neuroscience
- Respiratory Medicine
- Diagnostic Techniques
Background
- EUS-B utilizes echoendobronchoscopy for biopsies.
- It identifies anatomical landmarks for targeted sampling.
- The technique is designed to be patient-friendly with low discomfort.
- Safety is a primary concern, with no serious complications reported.
Purpose of Study
- To explore new biopsy techniques for difficult-to-access areas.
- To ensure conclusive biopsies with minimal adverse events.
- To enhance the investigation of patients with suspected lung cancer.
Methods Used
- Transesophageal ultrasound (EUS-B) technique.
- Identification of anatomical landmarks for biopsy.
- Assessment of safety and utility in clinical practice.
- Exploration of new targets for biopsy sampling.
Main Results
- EUS-B is a safe technique with no serious complications.
- It allows for a more comprehensive investigation of lung cancer.
- Patient comfort and safety are prioritized in the procedure.
- There are currently no simulators for training in EUS-B.
Conclusions
- EUS-B is an emerging technique in respiratory medicine.
- It offers a patient-friendly approach to biopsies.
- Further exploration and training methods are needed for its adoption.
Frequently Asked Questions
Executive Industry Relevance
Endobronchial ultrasound via the esophagus (EUS-B) expands minimally invasive access to mediastinal and abdominal structures for tissue sampling, supporting comprehensive diagnostic and staging workflows in oncology research. This technique enables pulmonologists to reach targets previously inaccessible by standard EBUS, enhancing the predictive confidence of biopsy-based assessments. EUS-B's integration into discovery and translational pipelines can reduce procedural risk and improve sample acquisition for molecular and biomarker studies.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Enables access to diverse anatomical sites for hypothesis-driven tissue sampling.
- Supports functional validation of disease-relevant targets in thoracic and abdominal regions.
- Facilitates biological de-risking by expanding the range of accessible lesions for analysis.
- Improves predictive confidence in target selection through comprehensive sampling.
Screening & Assay Development
- Provides high-quality biopsy material for downstream molecular and cellular assays.
- Standardizes sample acquisition from challenging anatomical locations.
- Enhances reproducibility of diagnostic and research assays by minimizing patient discomfort and adverse events.
- Enables scalable integration into multi-site screening protocols for oncology research.
Translational & Preclinical Research
- Aligns tissue sampling with translational biomarker discovery and validation needs.
- Supports continuity from clinical sampling to preclinical model development.
- Reduces risk of sampling bias by enabling access to metastatic and nodal sites.
- Facilitates risk-adjusted advancement decisions in early-stage oncology portfolios.
Pipeline & Workflow Integration
EUS-B positions tissue acquisition at the intersection of discovery biology, translational research, and clinical validation, bridging gaps in sample accessibility for oncology and immunology pipelines.
- Discovery Biology: Expands hypothesis testing by enabling biopsies from mediastinal, retroperitoneal, and abdominal sites.
- Screening: Delivers reproducible, high-quality samples for assay development and validation.
- Analytics: Provides quantitative outputs through real-time ultrasonographic guidance and fine needle aspiration.
- Translational Research: Aligns with biomarker and disease-relevant tissue requirements for preclinical and clinical studies.
- Enterprise Reuse: Offers a reusable, patient-friendly platform for multi-indication tissue sampling across R&D programs.
Operational & Enterprise Impact
- Scientific Value: Increases predictive confidence and reduces mechanistic ambiguity in target and biomarker validation.
- Operational Value: Standardizes minimally invasive sampling with high safety and reproducibility.
- Strategic Value: Enables better go/no-go decisions and capital efficiency by expanding diagnostic reach.
- Portfolio Impact: Supports risk-adjusted prioritization and advancement of oncology and immunology assets.
Implementation Considerations
- Requires expertise in endoscopic ultrasound and anatomical landmark identification.
- Needs access to echoendobronchoscopy instrumentation and real-time imaging infrastructure.
- Demands cross-team standardization for sample handling and procedural protocols.
- Adaptation across different anatomical models may require additional training resources.
- Lack of simulators or phantoms currently limits standardized training pathways.
