Prospective Trial Comparing the Diagnostic Yield of Two Different Needle Sizes Used in EBUS-TBNA for Sarcoidosis and Lymphoma

The guided FNA by endobronchial ultrasound ( Endobronchial Ultrasound guided transbronchial Needle Aspiration or EBUS-TBNA) is a minimally invasive technique with an established role in the staging of lung cancer 1, and in the evaluation of intrathoracic lymph node metastases from extrathoracic primary cancer2 . There is also a role in cases of isolated hilar and mediastinal lymph nodes in which the differential diagnosis includes mostly sarcoidosis, lymphoma and tuberculosis. 3

Various studies have evaluated more recently the diagnostic yield of EBUS-TBNA specifically for sarcoidosis 4 and thoracic lymphoma 5-6. Although there is emerging data supporting the usefulness of EBUS-TBNA in the investigation of these two pathologies, the efficacy results vary according to the target populations and certain parameters. Moreover, although a large randomized study demonstrated e superiority of EBUS-TBNA over conventional bronchoscopic sampling methods [ bronchoalveolar lavage (BAL) and trans-bronchial biopsies (TBB ] for the diagnosis of sarcoidosis , 7 the results suggest that there is still room for optimizing the performance of EBUS-TBNA [b] . In the field of lymphoma, obtaining large enough specimens for adequate subtyping also remains a concern. 8

In order to improve the performance of EBUS -TBNA , new needles have been developed with the aim to provide biopsies for histological evaluation rather than purely cytological. The ViziShot FLEX © (Olympus) 19 gauge needle (19 gauge or 19G) is a large needle, which can provide both tissue and needle aspiration , and has the advantage of being more flexible.

For this study, the investigators want to compare the diagnostic yield of EBUS-TBNA using needle ViziShot FLEX 19G (1.11 mm) with that of the standard 22G needle ( NA-201SX; Olympus) , in the investigation of hilar or mediastinal lymphadenopathy suspected to be sarcoidosis or lymphoma.