title: Flap prefabrication and prelamination with tissue-engineered cartilage.
abstract: In reconstructive surgery, the integration of tissue-engineered cartilage in a prefabricated free flap may make it possible to generate flaps combining a variety of tissue components, to meet the special requirements of particular defects. One aim of the present study was to investigate prefabrication of a microvascular free flap by implanting a vessel loop under a skin flap in a rabbit model. A second aim was to report on the authors' preliminary experiences in prelaminating prefabricated flaps with autologous tissue-engineered cartilage, in terms of matrix development, inflammatory reaction, and host-tissue interaction. The flap was prefabricated by implanting a vessel loop under a random-pattern abdominal skin flap. The tissue-engineered cartilage constructs were made by isolating chondrocytes from auricular biopsies. Following a period of amplification, the cells were seeded onto a non-woven scaffold made of a hyaluronic-acid derivative and cultivated for 2 weeks. One cell-biomaterial construct was placed beneath the prefabicated flap, and two additional constructs were placed subcutaneously and intramuscularly. In addition, a biomaterial sample without cells was placed subcutaneously to provide a control. All implanted specimens were left in position for 6 or 12 weeks. Neovascularization in the prefabricated flap and biomaterial construct was analyzed by angiography. After explantation, the specimens were examined by histologic and immunohistochemical methods. The prefabricated flaps showed a well-developed network of blood vessels between the implanted vessel loop and the original random-pattern blood supply. The tissue-engineered constructs remained stable in size and showed signs of tissue similar to hyaline cartilage, as evidenced by the expression of cartilage-specific collagen type II and proteoglycans. No inflammatory reactions were observed. The physiologic environment of the autologous rabbit model provided favorable conditions for matrix deposition and maturation of the cell-biomaterial constructs. These initial results demonstrated the potential of prefabricating an axial perfused flap, combined with tissue-engineered cartilage, thus creating functionally competent tissue components for reconstructive surgery with minimal donor-site morbidity.
authors.affiliation: ENT Department, University of Regensburg Hospital, Regensburg, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Staudenmaier
authors.forename: T Nguyen
authors.initials: TN
authors.lastname: Hoang
authors.forename: Norbert
authors.initials: N
authors.lastname: Kleinsasser
authors.forename: Christian
authors.initials: C
authors.lastname: Schurr
authors.forename: Kathrin
authors.initials: K
authors.lastname: Frölich
authors.forename: Magdalene M
authors.initials: MM
authors.lastname: Wenzel
authors.forename: Joachim
authors.initials: J
authors.lastname: Aigner
mesh_terms: D000792:Angiography; D000818:Animals; D002356:Cartilage / Q000254:growth & development* / Q000637:transplantation*; D018929:Cell Culture Techniques; D019902:Chondrocytes / Q000166:cytology; D024043:Collagen Type II / Q000378:metabolism; D023421:Models, Animal; D011509:Proteoglycans / Q000378:metabolism; D011817:Rabbits; D013524:Surgical Flaps / Q000098:blood supply*; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D024043:Collagen Type II; D011509:Proteoglycans