title: Esophagus tissue engineering: in situ generation of rudimentary tubular vascularized esophageal conduit using the ovine model.
abstract: OBJECTIVE
  Esophagus replacement using the present surgical techniques is associated with significant morbidity. Tissue engineering of the esophagus may provide the solution for esophageal loss. In our attempts to engineer the esophagus, this study aimed to investigate the feasibility of generating vascularized in situ esophageal conduits using the ovine model.
  
  
  METHODS
  Esophageal biopsies were obtained from lambs, and ovine esophageal epithelial cells (OEEC) were proliferated. The OEEC were seeded on to bovine collagen sheets preseeded with fibroblasts. After 2 weeks of maintaining the constructs in vitro, the constructs were tubularized on stents to create a tube resembling the esophagus and implanted into the omentum for in situ tissue engineering. The edges of the omentum were sutured using nonabsorbable suture material. The implanted constructs were retrieved after 8 and 12 weeks.
  
  
  RESULTS
  The omental wrap provided vascular growth within and around the constructs as they were integrated along the outer surface area of the scaffold. After removal of the stents, the engineered conduit revealed a structure similar to the esophagus. Histologic investigations demonstrated esophageal epithelium organization into patches on the luminal side and vascular ingrowths on the conduit's outer perimeter.
  
  
  CONCLUSIONS
  Our study demonstrated the seeding of OEEC on collagen scaffolds and formation of a rudimentary conduit resembling esophageal morphology after in situ omental implantation. Vascular coverage and ingrowth in the periphery of the construct could also be demonstrated. These findings hold future promise for the engineering of the esophagus with improved microarchitecture.
authors.affiliation: Department of Pediatric and Adolescent Surgery, Medical University of Graz, A-8036 Graz, Austria. amulya.saxena@medunigraz.at
authors.forename: Amulya K
authors.initials: AK
authors.lastname: Saxena
authors.forename: Hinrich
authors.initials: H
authors.lastname: Baumgart
authors.forename: Christian
authors.initials: C
authors.lastname: Komann
authors.forename: Herwig
authors.initials: H
authors.lastname: Ainoedhofer
authors.forename: Piotr
authors.initials: P
authors.lastname: Soltysiak
authors.forename: Kristina
authors.initials: K
authors.lastname: Kofler
authors.forename: Michael E
authors.initials: ME
authors.lastname: Höllwarth
mesh_terms: D000818:Animals; D003094:Collagen; D004933:Esophageal Atresia / Q000601:surgery; D004947:Esophagus / Q000098:blood supply; D006801:Humans; D018919:Neovascularization, Physiologic; D009852:Omentum; D020545:Respiratory Mucosa; D012756:Sheep; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds
chemical_list: D003094:Collagen