title: Factors related to diagnostic yield of transbronchial biopsy using endobronchial ultrasonography with a guide sheath in small peripheral pulmonary lesions.
abstract: OBJECTIVE
  To evaluate factors predicting the diagnostic yield of transbronchial biopsy (TBB) using endobronchial ultrasonography with a guide sheath (EBUS-GS) in small peripheral pulmonary lesions (PPLs) </= 30 mm in mean diameter.
  
  
  METHODS
  Retrospective analysis.
  
  
  METHODS
  One hundred fifty-five consecutive patients with 158 small PPLs underwent TBB using EBUS-GS.
  
  
  RESULTS
  A definitive diagnosis was established by TBB using EBUS-GS in 106 PPLs (67%). The diagnostic yield of PPLs </= 15 mm in mean diameter (40%) was significantly lower than that of PPLs > 15 mm and </= 30 mm in mean diameter (76%; p < 0.001). PPLs in which the probe was positioned within the PPL on the endobronchial ultrasonography (EBUS) image had a higher diagnostic yield (83%) than PPLs in which the probe was positioned adjacent to the PPL (61%) or outside the PPL (4%; p < 0.001). There were no significant differences in diagnostic yield for underlying disease, location, CT scan bronchus sign, operator, or type of EBUS probe. In the multivariate analysis, only the position of the probe (within or adjacent to the PPL when judged against outside the PPL) was determined to be a significant factor predicting diagnostic yield. On the other hand, a pathologic diagnosis was established with the first, second, third, fourth, and fifth biopsy specimens in 65%, 80%, 87%, 91%, and 97% of PPLs, respectively.
  
  
  CONCLUSIONS
  The position of the probe (ie, within or adjacent to the PPL) is a significant factor in predicting the diagnostic yield of TBB using EBUS-GS for small PPLs; the optimum number of biopsy specimens is at least five.
authors.affiliation: First Department of Medicine, Hokkaido University School of Medicine, North 15, West 7, Kitaku, Sapporo 060-8638, Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Yamada
authors.forename: Koichi
authors.initials: K
authors.lastname: Yamazaki
authors.forename: Noriaki
authors.initials: N
authors.lastname: Kurimoto
authors.forename: Hajime
authors.initials: H
authors.lastname: Asahina
authors.forename: Eiki
authors.initials: E
authors.lastname: Kikuchi
authors.forename: Naofumi
authors.initials: N
authors.lastname: Shinagawa
authors.forename: Satoshi
authors.initials: S
authors.lastname: Oizumi
authors.forename: Masaharu
authors.initials: M
authors.lastname: Nishimura
mesh_terms: D001706:Biopsy / Q000295:instrumentation; D001999:Bronchoscopy / Q000379:methods; D003937:Diagnosis, Differential; D019160:Endosonography; D004867:Equipment Design; D005336:Fiber Optic Technology; D006801:Humans; D008171:Lung Diseases / Q000000981:diagnostic imaging / Q000473:pathology*; D015203:Reproducibility of Results; D012189:Retrospective Studies