Besides the conventional 22-gauge (G) and 21G needles, a 25G needle is now available for endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). The objective of this study is to compare the efficiency of 22G and 25G EBUS-TBNA needles prospectively. We recruited 60 patients with mediastinal hilar lymph node involvement who were scheduled for EBUS-TBNA for diagnosis, and punctured the target lesions alternately with 22G and 25G needles. The diagnostic yields, sample volumes, complications, and sample quality of an equal number of punctures between the two needles were evaluated. Among 60 patients, 22 patients (37%) were diagnosed with malignant diseases, 34 patients (57%) were diagnosed with benign diseases, and 4 patients had uncertain diagnosis due to loss of follow up. The median number of comparison punctures of each needle was 2 (range: 1-3). The total diagnostic yield from histological and cytological findings were 80% (45/56) for 22G needles, and 71% (40/56) for 25G needles ( P = 0.189 ). The diagnostic yields were numerically higher using 22G needles compared with 25G needles, especially in benign diseases (malignant diseases; 86% (19/22) vs 82% (18/22), P = 0.50 , benign diseases; 76% (26/34) vs 65% (22/34), P = 0.213 , respectively). The mean tissue area obtained using 22G needles was significantly larger than that of 25G needles (0.68 mm 2 vs 0.31 mm 2 ) ( P<0.01 ). No severe bleeding was observed in this study. The use of a 25G needle may be less advantageous compared to a 22G needle, especially for the diagnosis of benign diseases, due to its smaller sample size.
Sakaguchi et al. (Wed,) studied this question.