title: Comparison of 21-gauge and 22-gauge Needles for Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration of Mediastinal and Hilar Lymph Nodes.
abstract: BACKGROUND
  : Although endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) using a 22-gauge needle has emerged as an accurate, minimally invasive, and safe technique for accessing undiagnosed mediastinal adenopathy, particularly in patients with lung cancer, the small sample size obtained by a conventional needle may limit the accuracy of the result.
  
  
  OBJECTIVE
  : We evaluated the safety and efficacy of obtaining specimens using 21-gauge needles, comparing diagnostic yield with conventional 22-gauge needles.
  
  
  METHODS
  : Participants consisted of 56 consecutive patients with mediastinal lesions referred to our institution for diagnostic EBUS-TBNA. The 21-gauge needle group (21 G) included 24 patients with 6 nonmalignancies and the 22-gauge needle group (22 G) included 32 patients with 9 nonmalignancies. Final diagnosis was based on cytology, histology, surgical results, appropriate clinical pictures on examination, and/or clinical follow-up.
  
  
  RESULTS
  : Comparing 21 G and 22 G, inadequate material rates were 0% versus 3.1% in cytology, and 4.2% versus 18.8% in histology, respectively. Accuracy in cytology, histology, and combined cytology and/or histology were 91.7% versus 65.6% (P=0.02), 95.8% versus 81.3% (P=0.11), and 100% versus 84.4% (P=0.04), respectively. After limiting cases to suspected malignancies, sensitivity in cytology, histology, and combined cytology and/or histology were 88.9% versus 52.2% (P=0.01), 100% versus 82.6% (P=0.09), and 100% versus 87.0% (P=0.17), respectively.
  
  
  CONCLUSIONS
  : Increasing sample volume using a 21-gauge needle rather than a 22-gauge needle might improve diagnostic yield in EBUS-TBNA. This study revealed the benefits of using a 21-gauge needle for cytological and histologic diagnostic yields.
authors.affiliation: *Division of Respiratory and Infectious Diseases, Department of Internal Medicine †Division of Chest Surgery, Department of Surgery, St Marianna University School of Medicine, Kawasaki, Japan.
authors.forename: Junko
authors.initials: J
authors.lastname: Saji
authors.forename: Noriaki
authors.initials: N
authors.lastname: Kurimoto
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Morita
authors.forename: Miho
authors.initials: M
authors.lastname: Nakamura
authors.forename: Takeo
authors.initials: T
authors.lastname: Inoue
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Nakamura
authors.forename: Teruomi
authors.initials: T
authors.lastname: Miyazawa