title: Meta-analysis of 21- versus 22-G aspiration needle during endobronchial ultrasound-guided transbronchial needle aspiration.
abstract: BACKGROUND
  Two different needle gauges (21 and 22 G) are currently used for endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). Few studies have compared the diagnostic utility of EBUS-TB107NA using 21 versus 22 G needles. We aimed to systematically analyze all existing literature comparing the diagnostic benefit of these 2 needles.
  
  
  METHODS
  A systematic search for the identification of all relevant studies comparing 21 and 22 G needles in EBUS-TBNA was performed using the MEDLINE, EMBASE, SCOPUS databases up to September 21, 2014. All the extracted data underwent meta-analysis using Review Manager 5.3 and Comprehensive Meta-analysis 3.3. Study-specific odds ratios (OR) were calculated and combined using random-effects model. Between study heterogeneity was assessed using the I statistic.
  
  
  RESULTS
  A total of 5 studies involving 1720 patients were identified. The sample adequacy rate was 89.1% in the 21 G group and 90.0% in the 22 G group and this difference was not statistically significant [OR, 0.94; 95% confidence interval (CI), 0.56-1.59; P=0.82]. Similarly, there was no significant difference in the diagnostic yield (73.7% vs. 58.5%; OR, 1.04; 95% CI, 0.80-1.35; P=0.80) or the mean number of needle passes (mean difference -0.31; 95% CI, -1.1 to 0.47; P=0.44). There were no major complications reported in any of these studies.
  
  
  CONCLUSIONS
  There were no differences in the diagnostic yield, sample adequacy, or the mean number of needle passes between the 21 and 22 G groups during EBUS-TBNA. Similarly, the complication rates were low and similar between the 2 groups.
authors.affiliation: *Department of Medicine §Department of Medicine, Division of Hematology/Oncology, University of Tennessee Health Science Center, Memphis, TN †Department of Medicine, Reading Health System, West Reading, PA ‡Department of Medicine, University of Kansas Medical Center, Kansas City, KS.
authors.forename: Smith
authors.initials: S
authors.lastname: Giri
authors.forename: Ranjan
authors.initials: R
authors.lastname: Pathak
authors.forename: Vivek
authors.initials: V
authors.lastname: Yarlagadda
authors.forename: Paras
authors.initials: P
authors.lastname: Karmacharya
authors.forename: Madan R
authors.initials: MR
authors.lastname: Aryal
authors.forename: Mike G
authors.initials: MG
authors.lastname: Martin
mesh_terms: D001999:Bronchoscopy / Q000295:instrumentation; D061765:Endoscopic Ultrasound-Guided Fine Needle Aspiration / Q000295:instrumentation*; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology*; D008198:Lymph Nodes / Q000473:pathology*; D008482:Mediastinum; D009339:Needles; D009367:Neoplasm Staging