Transplantation of Autologous Chondrocytes Seeded on a Fibrin/Hyaluronan Composite Gel Into Tracheal Cartilage Defects in Rabbits: Preliminary Results

Reconstruction of tracheal defects is one of the most difficult procedures in head and neck surgery. To date, various reconstructing techniques have been used with no consensus on the best approach. This study investigated the feasibility of using a fibrin/hyaluronic acid (HA) composite gel with autologous chondrocytes for tracheal reconstruction. Chondrocytes from autologous rabbit auricular cartilages were expanded and seeded into a culture dish at high density to form stable tracheal cartilages mechanically using a fibrin/HA composite gel. A 1-cm long by 0.5-cm wide defect was created by a scalpel on the cervical tracheae of six rabbits. Tissue-engineered cartilages using fibrin/HA composite were trimmed and fixed to the defect boundaries with tissuecol. Postoperatively, the site was evaluated endoscopically, histologically, radiologically, and functionally. None of the six rabbits showed signs of respiratory distress. Postoperatively, in all cases, rigid telescopic examination showed that the implanted scaffolds were completely covered with regenerated mucosa without granulation or stenosis. Histologically, the grafts showed no signs of inflammatory reaction and were covered with ciliated epithelium. Even when grafts were broken and migrated from their original insertion site, the implanted cartilages were well preserved. However, the grafts did show signs of mechanical failure at the implantation site. The beat frequency of ciliated epithelium on implants was very similar to that of normal respiratory mucosa. In conclusion, implants with autologous chondrocytes cultured with fibrin/HA showed good tracheal luminal contour, functional epithelial regeneration, and preservation of neocartilage without inflammation but lacked adequate mechanical stability.