Endobronchial ultrasound: Technical aspects
- Kazuhiro Yasufuku, MD, PhD
Kazuhiro Yasufuku, MD, PhD
- Associate Professor of Surgery
- University of Toronto
Endobronchial ultrasound (EBUS) is a bronchoscopic technique that uses ultrasound to visualize structures within and around the airway wall as well as the lung [1,2]. EBUS is different than endoscopic ultrasound (EUS). While both visualize and guide sampling of mediastinal lymph nodes, EBUS is performed during bronchoscopy and EUS is performed during gastrointestinal endoscopy. (See "Endoscopic ultrasound-guided fine-needle aspiration in the mediastinum".)
Types of EBUS and EBUS-guided sampling techniques are discussed in this topic review. The indications, contraindications, and complications of EBUS as well as the indications for EUS are discussed separately. (See "Endobronchial ultrasound: Indications, contraindications, and complications" and "Endoscopic ultrasound-guided fine-needle aspiration biopsy in the gastrointestinal tract".)
ADVANTAGES AND DISADVANTAGES
The main advantage of endobronchial ultrasound (EBUS)-guided sampling is that compared with surgical sampling, EBUS is a minimally-invasive, safe procedure that can be performed on an outpatient basis using local anesthesia and conscious sedation. In addition, EBUS can access a wide range of mediastinal lymph nodes as well as hilar lymph nodes (2R, 2L, 3p, 4R, 4L, 7, 10R, 10L, 11R, 11L) (figure 1 and figure 2), and sample centrally located pulmonary lesions with high sensitivity. (See "Endobronchial ultrasound: Indications, contraindications, and complications", section on 'Indications'.)
In contrast, EBUS cannot image or sample subaortic and paraesophageal lymph nodes. Its availability is institution-specific, and expertise is required to interpret images and obtain diagnostic samples. In addition, the negative predictive value (NPV) is not as high as surgical sampling, such that a negative sample should prompt the acquisition of tissue using an alternative modality (eg, surgical biopsy, mediastinoscopy). Additional limitations associated with EBUS-guided transbronchial needle aspiration (TBNA) that may contribute to the low NPV of EBUS (eg, small sample size) are discussed separately. (See "Procedures for tissue biopsy in patients with suspected non-small cell lung cancer", section on 'Limitations'.)
TYPES OF EBUS
Two types of endobronchial ultrasound (EBUS) exist: radial probe EBUS (RP-EBUS) and convex probe EBUS (CP-EBUS).
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- ADVANTAGES AND DISADVANTAGES
- TYPES OF EBUS
- Radial probe EBUS
- - Technique
- Convex probe EBUS
- - Technique
- SAMPLING TECHNIQUE
- Lymph nodes
- - Real-time TBNA with CP-EBUS
- - Sequential TBNA with RP-EBUS
- Parenchymal lesions
- - CP-EBUS-TBNA
- - RP-EBUS-guided transbronchial biopsy
- SUMMARY AND RECOMMENDATIONS