Endobronchial ultrasound (EBUS) is a minimally invasive diagnostic procedure which uses bronchoscopy and ultrasound technology to view lesions within the chest which are out of the airways. This is not possible using a normal bronchoscope which only identifies lesions within the airways. After visualizing the lesion, a needle is inserted into the lesion and it is sampled. The entire procedure can be performed without causing any discomfort to the patient
Endobronchial ultrasound enables the doctor to perform a procedure known as transbronchial needle aspiration to collect the required tissue or fluid samples from the lungs. This eliminates the need for any invasive surgery to obtain samples for biopsy. The samples collected through this technique are further analyzed to diagnose inflammatory diseases such as tuberculosis and sarcoidosis, and for diagnosing and staging cancers.
Endobronchial ultrasound is of two types. They are:
- Radial endobronchial ultrasound: It helps to analyze peripheral lung lesions. This type is especially useful to evaluate lesions in the terminal airway/lung parenchyma.
- Linear endobronchial ultrasound: It is useful for obtaining the samples of structures in the mediastinum (area of partition between the two lungs).
Both types of ultrasound contain a transducer head and a processor. The transducer helps to produce and receive the sound waves, while the processor combines the transmitted and reflected sound waves. The processor helps to create ultrasound images based on the absorption and scattering of the sound waves.
A. Linear EBUS: This has currently become the first line investigation of choice for sampling any mediastinal pathology. Most commonly sampled structures are the lymph nodes and centrally located masses. Rarely, EBUS may also be used to sample mediastinal cystic lesions.
B. Radial EBUS: This modality is used to visualize peripheral pulmonary nodules/masses or consolidations. Radial EBUS is usually combined with fluoroscopy/ Virtual bronchoscopic navigation for increasing the diagnostic yield.
Safety of endobronchial ultrasound
EBUS is one of the safest procedures in interventional pulmonology. Complications are usually related to sedation administered rather than the procedure per se.
The following are the benefits of endobronchial ultrasound:
- It provides real-time images of the airways, lungs, lymph nodes, and blood vessels.
- Gives high-definition images that help the doctor to visualize the damaged areas in the lungs more easily.
- Less duration of hospital stay, as it is a minimally invasive technique that is done under moderate sedation.
- Recovery is quick and the patients can go home within a few hours on the same day of the procedure.
- The doctor reviews the medical history and may order certain blood tests before the procedure.
- Also, the doctor would review your medications to make sure if any changes are required before the procedure.
- You will be advised to stop the use of blood thinning medications, such as aspirin and ibuprofen much before the procedure.
- The doctor would advise you to stop eating or drinking anything before a few hours of the procedure.
- Before beginning the procedure, you will be given anesthesia to relax the airways, which helps to insert the bronchoscope more easily.
- The doctor inserts a bronchoscope which is inserted through the mouth and passed through the windpipe into the bronchi.
- The bronchoscope is attached to a tiny camera and an ultrasound transducer at its end, which enables the doctor to view the airways, lymph nodes, blood vessels, and lungs on an ultrasound monitor.
- Also, the bronchoscope has a fine needle with which the doctor collects fluid or tissue samples from the lymph nodes. This procedure is known as transbronchial needle aspiration.
- It will take a few hours for you to be able to cough out after the procedure.
- There would be a feeling of soreness in the throat for a day.
- The doctor will send the collected tissue or fluid sample for further lab analysis.