Randomized Study of 21-gauge Versus 22-gauge Endobronchial Ultrasound-guided Transbronchial Needle Aspiration Needles for Sampling Histology Specimens

Background: Histologic specimens obtained by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) often provide valuable information for diagnosis or management decisions; however, little has been reported about the sampling yield. Besides the conventional 22-gauge needle, a 21-gauge needle is now available for this procedure. The purpose of this study was to elucidate and compare the respective histologic specimen retrieval yields of EBUS-TBNA using 21-gauge and 22-gauge needles. Methods: Sixty patients with hilar/mediastinal lymphadenopathy or a tumor adjacent to the central airway were enrolled and randomized to undergo EBUS-TBNA using a 21-gauge or a 22-gauge needle. Each histologic specimen obtained by EBUS-TBNA on the initial 2 punctures of each patient (total 120 punctures) was blindly categorized by a pathologist as follows: I, diagnostic; II, nondiagnostic but adequate (eg, lymphoid tissue); III, nondiagnostic and inadequate (eg, clot); and IV, no specimens. Results: The specimens obtained by the 21-gauge needle were interpreted as I in 35, II in 8, III in 15, and IV in 2. The specimens obtained by the 22-gauge needle were judged to be I in 34, II in 13, III in 7, and IV in 6. The sampling yield of adequate histologic specimens (I and II) obtained by the 21-gauge and 22-gauge needles was 72% and 78% (P=0.40), respectively. No complications were associated with the procedures. Conclusions: Histologic specimens can be obtained with a high sampling yield using either of the needles. Our study found no difference in the sampling yield between the 2 needles.