Comparison of Sample Adequacy and Diagnostic Yield of the 21-G and 25-G EBUS TBNA Needles.

BACKGROUND: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS TBNA) of mediastinal lymphadenopathy has been shown to be equivalent and possibly even superior to mediastinoscopy. Since the original dedicated 22-G aspiration needle, 21-G, 25-G, and recently 19-G needles have been introduced. Smaller needles may be more flexible and adept at accessing more difficult nodes, and may have less blood contamination compared with larger needles. PATIENTS AND METHODS: This is a prospective observational study of 50 consecutive patients who underwent endobronchial ultrasound-guided transbronchial needle aspiration with a 21-G needle and a 25-G needle for a total of 100 biopsies. The study slides were examined by a dedicated lung cytopathologist, who was blinded to the needle size used for each slide. Demographic data, and lymph node size were recorded. Comparisons between the 2 needles with regards to sample adequacy and diagnostic yield was performed using the McNemar test for dichotomous variables and marginal homogeneity test for nondichotomous variables since samples were related. RESULTS: The majority of lymph nodes (96%) were at least >1 cm. Adequate specimens were obtained in 78% of cases with the 21-G needle and 86% of cases with 25-G needle (P-value=0.424). The overall diagnostic yield was 74% and 80% with the 21-G needle and 25-G needle, respectively (P-value=0.607). CONCLUSION: Our study demonstrates that the there is no difference in terms of specimen adequacy and diagnostic yield when the 25-G needle is compared with the 21-G needle.