What is Endo Bronchial Ultrasound Guided Biopsy?
Endo Bronchial Ultrasound Guided Biopsy, often abbreviated to 'EBUS' or 'EBUS-TBNA' (see below) is a relatively new procedure which allows the diagnosis of conditions affecting the lungs, especially infections, inflammatory conditions such as sarcoidosis and types of cancer such as lymphoma lung cancer, all of which cause the lymph nodes in the lungs or chest to become enlarged. If cancer is present, a tissue sample will enable the assessment of the cancer stage.
In order to diagnose these conditions a biopsy procedure known as TBNA ('transbronchial needle aspiration') is used to collect either a tissue or fluid sample from the lungs and/or lymph nodes in the chest. EBUS is a minimally invasive procedure, that is it is conducted by inserting an endoscope (a thin tube) via the mouth and trachea (windpipe) into the airways.
How does it work?
EBUS uses ultrasound to obtain images of internal structures in the airways, the airway walls and the lungs in general, including the 'mediastinum', which is the membrane between the lungs. An ultrasound probe is inserted via the endoscope to visualise the internal structures and when the area where a biopsy is needed is identified, a special tool to take the tissue or fluid sample is inserted via the endoscope.
What are the advantages of the EBUS approach?
Prior to the introduction of the EBUS procedure, a surgical procedure known as a 'mediastinoscopy' was required to collect tissue and fluid samples (a mediastinoscopy may sometimes still be required - see below). This procedure requires a small incision to the neck and the insertion of a 'mediastinoscope' - a thin tube - to collect these samples. The advantages of the EBUS approach are...
- The procedure, as an endoscopic procedure, does not require any surgery and so can be completed on an outpatient basis under a local anaesthetic and conscious sedation
- Due to improved imaging capabilities, EBUS can examine in greater visual detail than other methods, and can access a number of areas inside the airways that the conventional mediastinoscopy cannot (althought there are a few internal 'sites' that EBUS cannot access and a mediastinoscopy can)
- The speed and accuracy of the EBUS approach means that tissue samples can be analysed during the procedure and further samples can be taken if needed
To see relevant details on how to prepare for the procedure, as well as what happens during the procedure and associated risks, please see the section on Bronchoscopy.