title: A strategy to improve the yield of transbronchial needle aspiration.
abstract: BACKGROUND
  Transbronchial needle aspiration (TBNA) is a bronchoscopic technique that provides access to masses within the mediastinum. It is operator dependent, and factors such as needle type, lymph node site, and endobronchial ultrasosonography (EBUS) have been implicated as having an impact on its accuracy. This study aimed to develop a strategy for TBNA and specimen preparation techniques as the first step toward improving TBNA yield, and to determine whether EBUS can augment its application.
  
  
  METHODS
  Intervention included standardizing the use of the histology needle and the direct smear method. As competency improved, radial probe (RP) and linear EBUS were incorporated into TBNA.
  
  
  RESULTS
  The study assessed 35 conventional TBNA procedures before and 45 of these procedures after intervention as well as 45 RP-EBUS and 50 linear EBUS-guided TBNA procedures. Frequently sampled lymph node stations were 7, 4R, and 4L in the American Thoracic Society classification. The preintervention conventional TBNA yield was 43%, which improved to 82% after intervention. Although EBUS did not have an impact on TBNA yield (p = 0.44) compared with the intervention (p = 0.001), EBUS was useful for lymph nodes smaller than 2 cm (p < 0.0001). Linear EBUS did not confer higher diagnostic accuracy than RP-EBUS (p = 0.47).
  
  
  CONCLUSIONS
  Proper TBNA and specimen preparation techniques are the first steps toward improving TBNA yield, and EBUS can be used to guide TBNA of small lymph nodes.
authors.affiliation: Department of Respiratory and Critical Care Medicine, Singapore General Hospital, Outram Road, Singapore, 169608, Singapore.
authors.forename: Ghee Chee
authors.initials: GC
authors.lastname: Phua
authors.forename: Kyung-Jae
authors.initials: KJ
authors.lastname: Rhee
authors.forename: Mariko
authors.initials: M
authors.lastname: Koh
authors.forename: Chian Min
authors.initials: CM
authors.lastname: Loo
authors.forename: Pyng
authors.initials: P
authors.lastname: Lee
mesh_terms: D044963:Biopsy, Fine-Needle / Q000379:methods*; D001999:Bronchoscopy / Q000295:instrumentation; D016009:Chi-Square Distribution; D019160:Endosonography; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology*; D008207:Lymphatic Metastasis; D008479:Mediastinal Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D009367:Neoplasm Staging; D013902:Radiography, Thoracic; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed