A vascularized tissue-engineered trachea with ectopic pedicled muscle flap

Objectives: Surgical treatment of segment tracheal reconstruction longer than 6 cm needs trachea substitutes, tissue engineering can provide alternatives for tracheal reconstruction. Constructs with blood supply are preferred for tracheal replacement. Here we describe an approach for engineering of vascularized trachea with ectopic pedicled muscle flap. Methods: Poly (L-lactic-co-glycolic acid) scaffolds were seeded with chondrocytes, cell-scaffold constructs were cultured in vitro for 2 weeks. In experiment group, cleidomastoid muscle was dissected with pedicle to wrap the cell-scaffold constructs. In control group, the constructs were simply implanted subcutaneously in the dorsum. After 4 weeks of in vivo culture, neotrachea were used for reconstruction of segmental tracheal defects. Results: A well-vascularized layer connecting with muscle flap was found in experiment group after in vivo culture, while in control group only connective tissue with fewer micro vascular could be found. After tracheal reconstruction, 3 animals in experiment group survived over six months, all the animals in control group died within one month. The mainly direct reason that caused animal death in control group was mucous impaction. Histological examinations revealed that poor epithelialization were observed in control group, the inner lumen surfaces were rough. Grafts in survival animals of experiment group showed a smooth inner lumen surface, covered by epithelium layer. Conclusion: Tissue-engineered trachea with pedicled muscle flap was transferred to the defect as a tracheal replacement and yielded satisfactory results, indicating that this approach may enable longterm functional reconstruction of tracheal defect.