title: Replacement of the left main bronchus with a tissue-engineered prosthesis in a canine model.
abstract: BACKGROUND
  Stenosis of the left main bronchus caused by inflammatory diseases and neoplasms is a serious clinical problem because it can cause obstructive pneumonia and may require pneumonectomy. As an alternative to various treatments currently available, including balloon dilatation, stenting, and bronchoplasty, we propose the use of a prosthesis developed based on the concept of in situ tissue engineering for replacement of the left main bronchus.
  
  
  METHODS
  The main frame of the tissue-engineered prosthesis is a polypropylene mesh tube, 12 to 15 mm in inner diameter and 30 mm in length, with reinforcing rings. Collagen extracted from porcine skin is conjugated to this frame. A consecutive series of 8 beagle dogs underwent replacement of the left main bronchus with this tissue-engineered prosthesis.
  
  
  RESULTS
  All dogs survived the postoperative period with no morbidity except 1, which required intravenous administration of antibiotic for a week for pneumonia and recovered. Three dogs were euthanized for examination at 3 and 4 months after bronchus replacement, and the other five were monitored for more than 1 year. In two dogs, histologic examination revealed that the luminal surface was completely covered with ciliated columnar epithelium or nonciliated squamous epithelium. Exposure of the polypropylene mesh to various degrees was observed in 6 dogs, but the prosthesis remained stable and no adverse effects such as infection, sputum retention, or dehiscence were observed.
  
  
  CONCLUSIONS
  These long-term results suggest that our tissue-engineered prosthesis is applicable for replacement of the left main bronchus.
authors.affiliation: Department of Bioartificial Organs, Institute for Frontier Medical Sciences, Kyoto University, Kyoto, Japan. tsato@frontier.kyoto-u.ac.jp
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Sato
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tao
authors.forename: Masato
authors.initials: M
authors.lastname: Araki
authors.forename: Hiroki
authors.initials: H
authors.lastname: Ueda
authors.forename: Koichi
authors.initials: K
authors.lastname: Omori
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Nakamura
mesh_terms: D000402:Airway Obstruction / Q000601:surgery; D000818:Animals; D001980:Bronchi / Q000473:pathology / Q000601:surgery*; D003251:Constriction, Pathologic; D004285:Dogs; D048091:Guided Tissue Regeneration; D011126:Polypropylenes; D019736:Prostheses and Implants; D011474:Prosthesis Design; D019919:Prosthesis Implantation; D013526:Surgical Mesh; D023822:Tissue Engineering
chemical_list: D011126:Polypropylenes