title: First Evaluation of the New Thin Convex Probe Endobronchial Ultrasound Scope: A Human Ex Vivo Lung Study.
abstract: BACKGROUND
  Endobronchial ultrasonography (EBUS)-guided transbronchial needle aspiration allows for sampling of mediastinal lymph nodes. The external diameter, rigidity, and angulation of the convex probe EBUS renders limited accessibility. This study compares the accessibility and transbronchial needle aspiration capability of the prototype thin convex probe EBUS against the convex probe EBUS in human ex vivo lungs rejected for transplant.
  
  
  METHODS
  The prototype thin convex probe EBUS (BF-Y0055; Olympus, Tokyo, Japan) with a thinner tip (5.9 mm), greater upward angle (170 degrees), and decreased forward oblique direction of view (20 degrees) was compared with the current convex probe EBUS (6.9-mm tip, 120 degrees, and 35 degrees, respectively). Accessibility and transbronchial needle aspiration capability was assessed in ex vivo human lungs declined for lung transplant. The distance of maximum reach and sustainable endoscopic limit were measured. Transbronchial needle aspiration capability was assessed using the prototype 25G aspiration needle in segmental lymph nodes.
  
  
  RESULTS
  In all evaluated lungs (n = 5), the thin convex probe EBUS demonstrated greater reach and a higher success rate, averaging 22.1 mm greater maximum reach and 10.3 mm further endoscopic visibility range than convex probe EBUS, and could assess selectively almost all segmental bronchi (98% right, 91% left), demonstrating nearly twice the accessibility as the convex probe EBUS (48% right, 47% left). The prototype successfully enabled cytologic assessment of subsegmental lymph nodes with adequate quality using the dedicated 25G aspiration needle.
  
  
  CONCLUSIONS
  Thin convex probe EBUS has greater accessibility to peripheral airways in human lungs and is capable of sampling segmental lymph nodes using the aspiration needle. That will allow for more precise assessment of N1 nodes and, possibly, intrapulmonary lesions normally inaccessible to the conventional convex probe EBUS.
authors.affiliation: Division of Thoracic Surgery, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada.
authors.forename: Priya
authors.initials: P
authors.lastname: Patel
authors.affiliation: Division of Thoracic Surgery, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada; Department of General Thoracic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors.forename: Hironobu
authors.initials: H
authors.lastname: Wada
authors.affiliation: Division of Thoracic Surgery, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada.
authors.forename: Hsin-Pei
authors.initials: HP
authors.lastname: Hu
authors.affiliation: Division of Thoracic Surgery, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Hirohashi
authors.affiliation: Division of Thoracic Surgery, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Kato
authors.affiliation: Division of Thoracic Surgery, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada.
authors.forename: Hideki
authors.initials: H
authors.lastname: Ujiie
authors.affiliation: Division of Thoracic Surgery, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada.
authors.forename: Jin Young
authors.initials: JY
authors.lastname: Ahn
authors.affiliation: Division of Thoracic Surgery, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada.
authors.forename: Daiyoon
authors.initials: D
authors.lastname: Lee
authors.affiliation: Department of Pathology, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada.
authors.forename: William
authors.initials: W
authors.lastname: Geddie
authors.affiliation: Division of Thoracic Surgery, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada. Electronic address: kazuhiro.yasufuku@uhn.ca.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yasufuku
mesh_terms: D001707:Biopsy, Needle; D001999:Bronchoscopy / Q000295:instrumentation*; D019160:Endosonography / Q000295:instrumentation*; D004867:Equipment Design; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging / Q000473:pathology*