title: Two-stage end-to-end reconstruction of long-segment tracheal defects with a bioabsorbable scaffold grafting technique in a canine model.
abstract: BACKGROUND
  When a long segment of trachea is resected and grafted with a bioabsorbable scaffold, chronic contraction of the graft occurs, leading to substantial delayed native tracheal axial approximation. This phenomenon may allow for safe two-stage end-to-end tracheal reconstruction of large tracheal defects. We performed this trial to confirm that delayed tracheal axial approximation occurs in a mature animal model and to test the surgical feasibility of two-stage end-to-end tracheal reconstruction.
  
  
  METHODS
  Five dogs (weight, 19 to 21 kg) underwent cervical tracheal resection and replacement (50 mm) with use of a conduit of a copolymer of L-lactide and ε-caprolactone reinforced with polyglycolic acid. A silicone stent (70 mm) was placed to prevent graft collapse. Postoperative bronchoscopy and computed tomography were scheduled to assess tracheal approximation and graft absorption. Native tracheal end-to-end reconstructive surgical procedures were planned at 9 months, when the defect that had been grafted decreased to less than 25 mm in length.
  
  
  RESULTS
  Suture-related granulation tissue in the airway of one dog, which prevented operation. The grafted area length in four animals ranged from 19 mm to 23 mm 9 months after operation. These animals then underwent tracheal reconstructive surgical procedures consisting of resection of the grafted area and end-to-end native tracheal reanastomosis without postoperative stent placement. All surgical procedures were successful, and there were no procedural deaths or postoperative complications after the second operation for as long as 2 months.
  
  
  CONCLUSIONS
  Delayed tracheal axial approximation after bioabsorbable grafting was confirmed in a mature animal model and allowed two-stage end-to-end tracheal reconstruction of large tracheal defects.
authors.affiliation: Division of Thoracic and Interventional Pulmonology, Beth Israel Deaconess Medical Center, Department of Surgery, Harvard Medical School, Boston, Massachusetts 02215, USA.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Tsukada
authors.forename: Adnan
authors.initials: A
authors.lastname: Majid
authors.forename: Michael S
authors.initials: MS
authors.lastname: Kent
authors.forename: Armin
authors.initials: A
authors.lastname: Ernst
authors.forename: Malcolm M
authors.initials: MM
authors.lastname: DeCamp
authors.forename: Sidhu P
authors.initials: SP
authors.lastname: Gangadharan
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D004285:Dogs; D023421:Models, Animal; D011474:Prosthesis Design; D019919:Prosthesis Implantation / Q000379:methods*; D019651:Plastic Surgery Procedures; D054457:Tissue Scaffolds; D014132:Trachea / Q000601:surgery*