[Experimental use of pulmonary flap with alloy stent for the reconstruction of trachea and esophagus].

OBJECTIVE

To study the feasibility of applying autogenous pulmonary tissue flap with alloy stent to correct the defects of trachea and esophagus.

METHODS

Twenty-four dogs were divided into tracheal and esophageal groups. Bronchus was ligated to prepare a pulmonary flap. And a defect of 3 - 4 cm long and 1/2 - 2/3 perimeter was made in tracheal or esophageal wall. Pulmonary arteries and veins were protected. Then the pulmonary gas was emitted to create a pulmonary tissue flap. The defect was repaired with a pulmonary flap with a self-expanded stent inside. The gross appearance, histological appearance, CT and barium X-ray films were observed at Weeks 2, 4, 6 and 8 post-operation.

RESULTS

Eighteen experimental dogs survived over 2 weeks. Anastomotic leak was the main cause of death. Two dogs died of perforation of ulcer in esophageal group. Reliable cicatrisation was observed between the pulmonary tissue flap and damage area. A quick growth of new tracheal and esophageal epithelium was observed from periphery area to central area. During the first 2 weeks, a little epithelization was observed at free edge of anastomosis equivalent to 1 - 2 layers of new epithelial cells. At weeks 4 - 6 post-operation, the internal surface of defect was covered with 3 - 5 layers of epithelial cells. At Weeks 8 - 10 post-operation, the luminal surface was covered with 6 - 8 layers of stratified epithelial cells. More ulcers could be observed on the surface of pulmonary tissue flap in esophageal group. In pulmonary flap, massive fibrous tissue proliferated and fibroblasts were active, but no necrosis occurred. CT and barium X-ray showed no obstruction in anastomotic stoma.

CONCLUSION

With an excellent compatibility with epithelial cells of trachea and esophagus, the autogenous pulmonary tissue flap can support the mucosal crawl in the defect of trachea and esophagus. When combined with alloy stent, it may be a choice procedure for reconstructing the defect of trachea and esophagus.