Objective: This study was designed to evaluate the ability of autologous tissue-engineered trachea shaped in a helix to form the structural component of a functional tracheal replacement.
Methods: Nasal septum were harvested from six 2-month-old sheep. Chondrocytes and fibroblasts were isolated from tissue and cultured in media for 2 weeks. Both types of cells were seeded onto separate nonwoven meshes of polyglycolic acid. The chondrocyte-seeded mesh was wound around a 20-mm-diameter x 50-mm-long helical template and then covered with the fibroblast-seeded mesh. In 2 separate studies the implants were placed either in a subcutaneous pocket in the nude rat (rat tissue-engineered trachea) or in the neck of a sheep (sheep tissue-engineered trachea). Rat tissue-engineered tracheas were harvested after 8 weeks and analyzed by means of histology and biochemistry. Sheep tissue-engineered tracheas were harvested from the neck at 8 weeks and anastomosed into a 5-cm defect in the sheep trachea.
Results: Sheep receiving tissue-engineered trachea grafts survived for 2 to 7 days after implantation. Gross morphology and tissue morphology were similar to that of native tracheas. Hematoxylin-and-eosin staining of rat tissue-engineered tracheas and sheep tissue-engineered tracheas revealed the presence of mature cartilage surrounded by connective tissue. Safranin-O staining showed that rat tissue-engineered tracheas and sheep tissue-engineered tracheas had similar morphologies to native tracheal cartilage. Collagen, proteoglycan, and cell contents were similar to those seen in native tracheal tissue in rat tissue-engineered tracheas. Collagen and cell contents of sheep tissue-engineered tracheas were elevated compared with that of normal tracheas, whereas proteoglycan content was less than that found in normal tracheas.
Conclusions: This study demonstrated the feasibility of recreating the cartilage and fibrous portion of the trachea with autologous tissue harvested from single procedure. This approach might provide a benefit to individuals needing tracheal resection.