Development of tracheal reconstruction methods from scaffold engineering to injectable matrix

Backgrand: For patients with long segment of tracheal stenosis, resection and replacement is necessary. Tracheal reconstruction associated with complications such as stenosis, insufficiency of blood supply and surgical complication. Methods: In this study, we prepared collagen-chitosan scaffold and sheep's decellularized trachea plus culture medium with nanocup contain growth factors for chondrocyte and fibroblast-epithelial cell culture in rotary bioreactor. After attachment of cells, engineered trachea put into the omentum. Peritoneal stem cell interact with the epithelial and chondrocytes with attendance of growth factors released from nanocup. The bioengineered trachea with omental pedicle transposed from behind the sternum and transplanted in the position of resected trachea. In third experiment, we introduce the in situ tracheal repair technique with injectable matrix for reconstruction of long-segmental stenosis of trachea in a 29-year-old woman. Results: Severe tortuosity in the first experiment and mild stenosis was seen in the second experiment. In third experiment, normal shape in tracheal diameter was seen at injection sites. The interior portion of the trachea at virtual computed tomography (CT) scan and bronchoscopy were similarity to normal after four month fallowing up of injection. Conclusions: Severe tortuosity, mild stenosis in whole length of trachea in this study and disadvantage of trachea transplantation include open surgery, fatal consequences of anastomosis leakage, and rupture besides large mediastinal vessels; hence, we decided to introduce the novel in situ tracheal repair technique. Injectable bioresorbable scaffolds may be used as a temporary scaffolding for transplanted cells and thereby allow the cells to secrete extracellular matrix of their own to enable, in the long term, a complete and natural tissue replacement.