title: Comparison of radial endobronchial ultrasound with a guide sheath and with distance by thin bronchoscopy for the diagnosis of peripheral pulmonary lesions: a prospective randomized crossover trial.
abstract: BACKGROUND
  Transbronchial biopsy (TBB) using radial endobronchial ultrasound with a guide sheath (REBUS-GS) has improved the diagnosis of peripheral pulmonary lesions (PPLs). Because of the high cost of the GS, REBUS with distance (REBUS-D) has certain advantages. The aim of this study was to compare the diagnostic yield of the REBUS-GS and REBUS-D by thin bronchoscopy for PPLs.
  
  
  METHODS
  Patients with PPLs were enrolled in a prospective randomized crossover study from August 2014 and July 2015. Once the lesion was localized, TBB using REBUS-GS and TBB using REBUS-D were performed sequentially in a randomized order in each patient. Each patient received four to five transbronchial biopsies with REBUS-GS as well as four to five transbronchial biopsies with REBUS-D. All brushing was performed through GS.
  
  
  RESULTS
  A total of 54 patients were enrolled in this study. After excluding seven participants with PPLs that were not detected by REBUS, a total of 47 subjects underwent REBUS-TBB. The diagnostic yield of REBUS-GS-TBB and REBUS-D-TBB was 72.2% (39/54) and 75.9% (41/54) respectively (P=0.625). Moreover, there was no statistically significant difference in diagnostic yield between REBUS-GS and REBUS-D in different lobe lesions and lesion sizes. Two cases of adenocarcinoma were only diagnosed with REBUS-GS-TBB. Two cases of tuberculosis, one case of mucosa-associated lymphoid tissue lymphoma (MALT) and one case of adenocarcinoma were only diagnosed by REBUS-D-TBB. The mean biopsy time after visualization of PPLs for REBUS-GS-TBB and REBUS-D-TBB were 5.17±2.34 and 7.36±3.18 min (P=0.00053).
  
  
  CONCLUSIONS
  Using thin bronchoscopy, the diagnostic yield for PPLs with REBUS-D-TBB is not inferior to the yield with REBUS-GS-TBB. The diagnosis rate of small subpleural lesions with REBUS-D is lower than the rate with REBUS-GS. Although it is associated with shorter operation time and less bleeding, REBUS-GS has a higher cost and sometimes leads to check failure due to small specimens and the impact of the bronchoscope curvature.
authors.affiliation: Department of Respiratory Medicine, the Third Affiliated Hospital of Soochow University, Changzhou 213003, China.
authors.forename: Su-Juan
authors.initials: SJ
authors.lastname: Zhang
authors.affiliation: Department of Respiratory Medicine, the Third Affiliated Hospital of Soochow University, Changzhou 213003, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Department of Respiratory Medicine, the Third Affiliated Hospital of Soochow University, Changzhou 213003, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Department of Respiratory Medicine, the Third Affiliated Hospital of Soochow University, Changzhou 213003, China.
authors.forename: Qiu-Di
authors.initials: QD
authors.lastname: Zhang
authors.affiliation: Department of Respiratory Medicine, the Third Affiliated Hospital of Soochow University, Changzhou 213003, China.
authors.forename: Qian-Qian
authors.initials: QQ
authors.lastname: Xu
authors.affiliation: Department of Respiratory Medicine, the Third Affiliated Hospital of Soochow University, Changzhou 213003, China.
authors.forename: Xiong
authors.initials: X
authors.lastname: Xu
keywords: Radial endobronchial ultrasound (REBUS); guide sheath (GS); peripheral pulmonary lesions (PPLs); thin bronchoscopy; transbronchial biopsy (TBB)