Utilization of cartilage sheets for localized tracheal defect repair in a goat model

Background: Repairing tracheal defects remains a significant challenge in tracheal surgery. Previous attempts using traditional tissueengineered tracheal scaffolds in large animal models have largely failed due to inflammation and insufficient mechanical properties. Methods: In this study, we propose a novel approach that uses cell sheet technology to construct scaffold-free cartilage sheets in vitro. These sheets are stacked and then implanted into goats for further maturation, resulting in large neocartilage tissue with mechanical properties comparable to native tracheal cartilage. We evaluated three methods of tracheal defect repair in goat models using the stacked cartilage sheets: (1) In situ repair with stacked cartilage sheets without vascular pedicle; (2) In situ repair with stacked cartilage sheets and preservation of the vascular pedicle; (3) In situ repair with stacked cartilage sheets, preservation of the vascular pedicle, and T-tube insertion. Results: Airway stability was successfully restored in all animals, with all goats surviving until the end of the experiment without surgery-related complications. Goat 1 exhibited significant granulation tissue hyperplasia compared to goats 2 and 3. The airway morphology was best maintained in goat 3, which showed the highest degree of re-epithelialization, followed by moderate reepithelialization in goat 2, and minimal in goat 1. Conclusions: These results suggest that stacked cartilage sheets are a viable option for tracheal repair, with vascular pedicle preservation and T-tube insertion enhancing therapeutic outcomes. Our study represents the first successful use of scaffold-free cartilage sheets for tracheal repair and provides a theoretical foundation for applying this technology in tracheal reconstruction.