A Prospective, Randomized Trial for the Comparison of 19-G and 22-G Endobronchial Ultrasound-Guided Transbronchial Aspiration Needles; Introducing a Novel End Point of Sample Weight Corrected for Blood Content.

BACKGROUND: The use of 22- or 21-gauge (G) endobronchial ultrasound (EBUS) needles are recommended for lung cancer diagnosis and staging. Performance of detailed molecular workup and programmed death ligand 1 (PD-L1) staining in lung cancer patients increases the demand for tissue. The aim of this prospective, randomized two-center trial was to compare 19-G and 22-G EBUS needles regarding tissue quality, diagnostic yield, feasibility, safety, performance, and blood content.

PATIENTS AND METHODS: Patients with a computed tomography scan indicative of lung cancer with mediastinal or hilar lymph node metastases were prospectively enrolled and randomized for the use of either a 19-G or a 22-G EBUS needle. A blood content score from 0 to 2 was applied. Samples were weighed, tumor cells were counted per slide, and complications and final diagnoses were documented.

RESULTS: We enrolled 107 patients (53 [49.5%] in the 19-G group/54 [50.5%] in the 22-G group) and samples were weighed immediately after performing EBUS. Samples obtained with a 19-G needle contained significantly more tissue (P = .0119). Non-small-cell lung cancer-infiltrated EBUS samples contained significantly more tumor cells when sampled with a 19-G needle (P = .0312). The diagnostic yield was equally adequate in both groups. Four moderate EBUS-related bleedings occurred (2 per group), hemostasis was rapidly achieved in all cases. Further complications did not occur.

CONCLUSION: Endobronchial ultrasound-guided transbronchial needle aspirations with a 19-G needle contain significantly more tissue and tumor cells per slide with a safety profile similar to 22-G needles. Further research is needed to investigate the relevance of this finding in terms of molecular analyses and PD-L1 staining.