title: Tracheal reconstruction with a composite graft: fascial flap-wrapped allogenic aorta with external cartilage-ring support.
abstract: OBJECTIVE
  Animal and clinical studies have demonstrated the feasibility of tracheal replacement by silicone-stented allogenic aortas. In clinical trials, however, this graft did not show mature cartilage regeneration into the grafts as was observed in animal models. To solve this issue, we investigated tracheal replacement with a composite graft based on a fascial flap-wrapped allogenic aorta with external cartilage-ring support in a rabbit model.
  
  
  METHODS
  Seven male 'Géant des Flandres' and 'New Zealand' rabbits served as donors of aortas and cartilage rings, respectively. Nineteen female 'New Zealand' rabbits were used as recipients. First, in nine animals, neoangiogenesis of the composite graft following a wrap using a pedicled lateral thoracic fascial flap and implantation under the skin of the chest wall was investigated. Animal sacrifice was scheduled at regular intervals up to 38 days. Second, 10 animals underwent tracheal replacement with the composite graft after a 7-to-9 day revascularization period, and were followed-up to death. Macroscopic and microscopic examinations were used to study the morphology, stiffness and viability of the construct.
  
  
  RESULTS
  There was one operative death after tracheal replacement. The first group of animals was found to have a satisfactory tubular morphology and stiffness of their construct associated with preserved histological structure of cartilages and moderate to severe aortic ischaemic lesions. In the group of rabbits having undergone tracheal replacement, the anatomical results were characterized by a discrepancy between the severity of ischaemic lesions involving both allogenic aorta and cartilage rings and the satisfactory biomechanical characteristics of the graft in 7 of 10 animals, probably due to cartilage calcification deposits associated with inflammatory scar tissue ensuring the stiffness of the construct.
  
  
  CONCLUSIONS
  Our investigations demonstrate the feasibility of the replacement of circumferential tracheal defects using our composite graft. Future experiments using therapeutic bronchoscopy tools are required to draw conclusions regarding the effectiveness of this tracheal substitute in the long-term.
authors.affiliation: IMPRT-IFR 114, EA 2693, University of Lille-North of France, Lille, France. alain.wurtz@chru-lille.fr
authors.forename: Alain
authors.initials: A
authors.lastname: Wurtz
authors.forename: Ilir
authors.initials: I
authors.lastname: Hysi
authors.forename: Eric
authors.initials: E
authors.lastname: Kipnis
authors.forename: Christophe
authors.initials: C
authors.lastname: Zawadzki
authors.forename: Thomas
authors.initials: T
authors.lastname: Hubert
authors.forename: Ramadan
authors.initials: R
authors.lastname: Jashari
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Copin
authors.forename: Brigitte
authors.initials: B
authors.lastname: Jude
mesh_terms: D000818:Animals; D001013:Aorta, Thoracic / Q000473:pathology / Q000637:transplantation*; D001696:Biomechanical Phenomena; D002356:Cartilage / Q000473:pathology / Q000637:transplantation*; D005205:Fascia / Q000098:blood supply / Q000473:pathology; D000071938:Fasciotomy; D005240:Feasibility Studies; D005260:Female; D006085:Graft Survival; D008297:Male; D023421:Models, Animal; D018919:Neovascularization, Physiologic; D011817:Rabbits; D019651:Plastic Surgery Procedures / Q000379:methods*; D013524:Surgical Flaps / Q000098:blood supply; D013997:Time Factors; D014132:Trachea / Q000473:pathology / Q000637:transplantation*