Endobronchial ultrasound

Abstract

Endobronchial ultrasound (EBUS) is a relatively new procedure used in the diagnosis of lung cancer, lung infections, and other diseases that cause enlarged lymph nodes or masses in the chest. The EBUS procedure allows physicians to perform a technique known as transbronchial needle aspiration (TBNA) to obtain tissue samples from the lungs and surrounding lymph nodes without conventional surgery.The samples can be used for diagnosing and staging lung cancer, detecting infections, and identifying inflammatory diseases that affect the lungs, such as sarcoidosis. During a conventional diagnostic procedure, a surgical procedure known as a mediatinoscopy is performed to provide access to the chest. A small incision is made in the neck just above the breastbone or next to the breastbone. Next, a thin scope, called a mediastinoscope is inserted through the opening to provide access to the lungs and surrounding lymph nodes. Tissue is then collected via biopsy. During the EBUS procedure however, the physician can perform a needle biopsy on lymph nodes using a bronchoscope inserted through the mouth. For the EBUS procedure, a special endoscope is fitted with an ultrasound processor and a fine-gauge aspiration needle is guided through the patient’s trachea. No incisions are necessary. The ultrasound display provides real-time imaging of the surface of the airways, blood vessels, lungs, and lymph nodes. The images allow the physician to view difficult-to-reach areas and to access more, and smaller, lymph nodes than through a conventional mediatinoscopy. Procedure An EBUS is a procedure that allows the doctor to look into your lungs (similar to a bronchoscopy) but them to take samples of the glands in the centre of your chest (mediastinum) using the aid of an ultrasound scan, these glands lie outside the normal breathing tubes (bronchi). A flexible tube (bronchoscope), which is about the size of a man’s little finger, is passed into your lungs via your mouth (you will have a mouthguard and some protective glasses on) with you lying as flat as possible. A small camera at the end of the bronchoscope enables the doctor to look directly into your windpipe (trachea) and breathing tubes (bronchi). A small ultrasound probe on the end of the camera allows the doctor to see the glands in the centre of the chest (mediastinum) and take samples under direct vision. Occasionally, it is useful to look down your esophagus at the same time with the same camera (the anesthetic in your throat allows this), as sometimes the glands can be sampled from the gullet which often causes less coughing and is more comfortable for patient with breathing difficulties (if this is a possibility, it would be discussed with you beforehand by the doctor). Most commonly, Endobronchial ultrasound-guided transbronchial needle aspiration is done to take samples from the central lymph glands in the centre of your chest (mediastinum) which may be enlarged for a variety of reasons. In 9 out of 10 cases, we would expect this test to give a helpful answer to the problem. Very occasionally, another test may be needed.