Objective To study the protective effects and mechanism of intermittent ventilation on lung injury during cardiopulmonary bypass(CPB). Methods Twenty-four patients with rheumatic heart disease (RHD) were divided into two groups with random number table: treatment group (n=13),given intermittent ventilation once every 5 minutes during CPB; control group (n=11),no ventilation during CPB. Blood samples were obtained preoperatively. A bronchoalveolar lavage was performed at 2 hours after CPB. The numbers of granulocytes, total protein (TP) and tumor necrosis factor-alpha(TNF-α) content in the bronchoalveolar lavage fluids(BALF) were measured, and lung oxygenate index (OI) were measured preoperatively and 1 hour, 4 hours after CPB termination,respectively. Results The numbers of granulocytes, TP and TNF-α content of treatment group in the BALF were significantly lower than those of the control group (Plt;0.01, P=0.02,0.02),and the lung OI of treatment group at 1 hour and 4 hours after CPB termination was also significantly lower than that of the control group(Plt;0.05); a significant increase of lung OI occurred in both groups at 1 hour and 4 hours after CPB when compared with the same group at baseline before CPB(Plt;0.05). Conclusion Intermittent ventilation has the protective effects on lung injury during CPB by decreasing granulocytes adhesion and alleviating lung inflammatory reaction and endothelial cells injury.
Objective To construct a new composite artificial trachea and to investigate the feasibility of trachea repair and reconstruction with the new composite artificial trachea transplantation in dogs. Methods The basic skeleton of the new composite artificial trachea was polytetrafluoroethylene vascular prosthesis linked with titanium rings at both ends. Dualmesh was sutured on titanium rings. Sixteen dogs, weighing (14.9 ± 2.0) kg, female or male, were selected. The 5 cm cervical trachea was resected to prepare the cervical trachea defect model. The trachea repair and reconstruction was performed with the new composite artificial trachea. Then fiberoptic bronchoscope examination, CT scan and three-dimensinal reconstruction were conducted at immediate, 1 month, and 6 months after operation. Gross observation and histological examination were conducted at 14 months to evaluate the repair and reconstruction efficacy. Results No dog died during operation of trachea reconstruction. One dog died of dyspnea at 37, 41, 55, 66, 140, and 274 days respectively because of anastomotic dehiscence and artificial trachea displacement; the other 10 dogs survived until 14 months. The fiberoptic bronchoscope examination, CT scan and three-dimensinal reconstruction showed that artificial tracheas were all in good location without twisting at immediate after operation; mild stenosis occurred and anastomoses had slight granulation in 6 dogs at 1 month; severe stenosis developed and anastomosis had more granulation in 1 dog and the other dogs were well alive without anastomotic stenosis at 6 months. At 14 months, gross observation revealed that outer surface of the artificial trachea were encapsulated by fibrous connective tissue in all of 10 dogs. Histological examination showed inflammatory infiltration and hyperplasia of fibrous tissue and no epithelium growth on the inner wall of the artificial trachea. Conclusion The new composite artificial trachea can be used to repair and reconstruct defect of the trachea for a short-term. Anastomotic infection and dehiscence are major complications and problems affecting long survival.