How is convex probe endobronchial ultrasound (CP-EBUS) performed?

Updated: Apr 24, 2019
  • Author: Narayan Neupane, MD; Chief Editor: Zab Mosenifar, MD, FACP, FCCP  more...
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Answer

Answer

Convex probe EBUS (CP-EBUS) is usually performed orally, because the ultrasound probe prevents use of the nasal route. The image quality of CP-EBUS is lower than that of regular bronchoscopy. A disposable latex balloon is attached to the ultrasound probe. The tip of the bronchoscope should be positioned anteriorly while passing it through the vocal cords to prevent the EBUS bronchoscope from sticking to the posterior part of the vocal cords. Once in the airway, a syringe filled with sterile water is attached to the balloon channel of the scope, and the balloon is filled with water to achieve contact with the airways.

The lymph nodes should be differentiated from vascular structures, which are also hypoechoic. Doppler ultrasound accurately differentiates lymph nodes from vascular structures. All mediastinal lymph node stations should be evaluated systematically. The subcarinal lymph node can be visualized either from the right main or left main bronchus. The bronchoscopic and ultrasound views can be toggled alternatively, or a 2-screen display can be used for simultaneous viewing. The tip should be flexed up for and ultrasound image and down for an endoscopic image. The ultrasound image can be frozen, allowing lesions to be measured.


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