title: Randomized Study of 21-gauge Versus 22-gauge Endobronchial Ultrasound-guided Transbronchial Needle Aspiration Needles for Sampling Histology Specimens.
abstract: 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.
authors.affiliation: *Department of Respiratory Medicine †Department of Pathology, Nagoya Medical Center, Nagoya ‡Kyoto University Health Service, Kyoto, Japan.
authors.forename: Masahide
authors.initials: M
authors.lastname: Oki
authors.forename: Hideo
authors.initials: H
authors.lastname: Saka
authors.forename: Chiyoe
authors.initials: C
authors.lastname: Kitagawa
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Kogure
authors.forename: Naohiko
authors.initials: N
authors.lastname: Murata
authors.forename: Shu
authors.initials: S
authors.lastname: Ichihara
authors.forename: Suzuko
authors.initials: S
authors.lastname: Moritani
authors.forename: Masahiko
authors.initials: M
authors.lastname: Ando