Objective: The ideal method, in reconstruction of circumferential tracheal defects more than 50% of the total tracheal length, is still a question. Current methods lack either in epithelial lining or in skeletal framework. In this study, we designed an axial biosynthetic prefabricated flap to reconstruct the circumferential tracheal defects in rabbits.
Methods: Ten rabbits are used. The inner mucosal lining is substituted by hairless epithelium obtained from proximal ear. The tracheal cartilage is substituted by polypropylene mesh and the tracheal adventitia is substituted by lateral thoracic fascia as a vascular supply. The study is designed in three stages. Stage 1: Hairless epithelial graft is obtained by secondary healing of a full thickness skin defect in ear. Stage 2: Epithelial graft, polypropylene mesh and lateral thoracic fascia are tubed around a silicone catheter. This structure is dissected through its pedicle (lateral thoracic vessels and fascia) to the axilla and mobilized. The prefabricated neotrachea is carried on its pedicle to the cervical area through a subcutaneous tunnel formed superficial to the sternum and left there for 2 weeks. Stage 3: The silicone catheter is taken out and prefabricated neotrachea is adapted to the defect formed in native trachea and anastomized. Later the animals are evaluated for 4 weeks. The patency of the lumen, the viability of the epithelial graft and fascia, airtightness of the anastomoses and other features of the reconstruction are evaluated by radiological, macroscopical and histological examinations.
Results: Survival at 4 weeks was 70%. All of the prefabricated neotracheas and epithelial grafts were viable. The rigidities, longitudinal elasticities, diameters and wall thickness were similar to native tracheas. Occlusion of lumen is encountered only in one animal. There was no hair growth from the epithelial lining.
Conclusion: The study defines a new method of circular tracheal reconstruction with successful substitution of inner lining, skeletal framework and vascular supply.