Objective To develop a tissue engineering scaffold by using 4arm branched polyethylene glycol-VS (PEG-VS) crosslinked with decellularized valved conduits (DVC), and to research on its mechanical and biological functions. Methods The valved aortic conduits of rabbits were taken and decellularized by trypsin method and then were crosslinked with 4arm branched PEG-VS to construct the composite scaffolds (CS). The functions of decellularized valved conduits and the composite scaffolds were tested by mechanics test system. Thirty New Zealand white rabbits were equally and randomly assigned to one of the three groups: the control group, the DVC group, and the CS group. Valved aortic conduits, decellularized valved conduits and composite scaffoldswere transplanted into the common carotid artery of the abovementioned three groups of rabbits respectively. Twentyeight days after the operation, patency of the transplants was tested by Color Doppler ultrasound; micromorphology and inflammatory infiltration were observed by hematoxylin eosin（HE） staining andscanning electron microscope (SEM)，and endothelialization of composite scaffolds was detected by immunofluorescent staining. Results A series of biomechanical analyses revealed that the composite scaffolds had highly similar mechanical properties as fresh tissue, and had superior elastic modulus (P=3.1×10-9) and tensile strength (P=1.1×10-6) compared with decellularized valved conduits. Color Doppler ultrasound revealed that the graft patency for the CS group was better than the control group (P=0.054) and the DVC group (P=0.019), and the intraaortic thrombosis rate and distortion rate decreased significantly. HE staining and SEM showed that the endothelialization of composite scaffolds in the CS group was significantly higher than the other two groups with the endothelial cells evenly distributed on the scaffolds. The [CM(159mm]immunofluorescent staining indicated that the positive rate of the endothelial cell marker CD34 was higher than the other two groups. Conclusion The composite scaffolds using 4arm branched PEGVS crosslinked with DVC have great mechanical and biological properties.
Objective To modify the sewing technique of a hand-made bicuspid pulmonary valve using the expanded polytetrafluoroethylene in right ventricle outflow tract reconstruction for summarizing the short-term experience. Methods The patients with complex congenital heart diseases and concurrent contaminant pulmonary regurgitation that underwent right ventricle outflow tract reconstruction through the bicuspid pulmonary valve were enrolled. The postoperative artificial valve function and right ventricle function indexes were evaluated. Results A total of 17 patients were collected, including 10 males and 7 females, with an average age of 18.18 years and an average weight of 40.94 kg. Of 17 patients, 16 used valved conduit for the reconstruction of the right ventricle outflow tract with the size ranging from 18 to 24 mm. There was no patient requiring mechanical circulatory support and no in-hospital death. During the follow-up with a mean period of 12.89 months, only one vale dysfunction occurred without any complications and adverse events (P<0.001). Postoperative right atrium diameter, right ventricle diameter, and tricuspid regurgitation area significantly decreased in contrast to those preoperatively (P<0.05). Conclusion Sewing the bicuspid pulmonary valve utilizing 0.1 mm expanded polytetrafluoroethylene is a feasible, effective, and safe technique of right ventricle outflow tract reconstruction in the field of complex congenital heart diseases.