TISSUE ENGINEERING PERICARDIUM

各种血管移植常用于心血管组织重建。然而，目前使用的假体或生物假体材料缺乏生长潜力，因此，在儿童器官成熟后需要更换。组织工程（YE）是一门新的学科，它提供了创造自体细胞和可识别聚合物支架的替代结构的潜力。由于这种结构含有活细胞，它们可能具有生长、自我修复和自我重塑的潜力，因此将从犬股静脉中获得的4-6 × 10^6的混合细胞植入到由聚乙二醇酸（PGA）无纺布片和l-丙交酯和内酯共聚物组成的管状可生物降解聚合物支架上，制成组织工程血管自体移植物（TEVAs）。7 d后，将同一组狗的下腔静脉（IVCs）替换为teva。后3、4。5、6个月时进行血管造影检查，犬均有明显损伤。对植入的teva进行粗观和免疫组织学检查。植入的teva没有出现狭窄或扩张的迹象。teva内未见血栓形成。即使没有任何抗凝治疗。在所有标本中均未观察到聚合物支架的残余，总体大体外观与天然IVCs相似。免疫组织学染色显示在teva的管腔表面存在因子VIII阳性诱导细胞。此外，在α-平滑肌肌动蛋白和desmin阳性细胞处观察病变。植入的teva含有足够的细胞外基质，未出现闭塞和动脉瘤形成。此外。内皮细胞排列在每个TEVA的管腔表面。这些结果强烈提示可以产生具有抗血栓形成性的“理想”静脉移植物。使用tetedmique，我们成功地用自体静脉细胞重建了一名4岁女孩的肺动脉外周动脉。血管移植重建闭塞的肺动脉，术后无并发症。随访血管造影显示，移植血管完全通畅。以同样的方法，用生物可降解聚合物片在动物模型中检测了自体心包。与假体材料相比，心包粘连相对较轻。由于我们的实验室和临床经验都非常令人鼓舞，我们建议在儿科心血管手术领域，TE方法可能作为移植和人工器官使用的替代方法发挥重要作用。少

Various vascular grafts am commonly used in the reconstruction of cardiovascular tissues. However, cunently used prosthelic or bioprosthetic materials lack giowth potential and, therefore, subsequently requie replacement in pediatric Talients as they matrure. Tissue engineering (YE) isa new discipline that offers the potential to create replacement structures ficm autologous cells and bkxlegiadable polymer scaffolds. Because Th constructs contain living cells, they may have the potential to grow, self-repair, and self-remodel, Tissue Engineered Vascular Autografts (TEVAs) were made by seeding 4-6 x 10^6 of mixed cells obtained fiom femoral veins of mongiel dogs onto tube-shaped biodegradable polymer scaffolds composed of a polyglyecolic acid (PGA) non-woven fabric sheet and a co-polymer of l-lactide andcapolactone (N=4). After 7 days, the inferior vena cavas (IVCs) of the same dogs were replaced with TEVAs. After 3,4. 5 and 6 months, angiographies were perfomed, and the dogs were sacii … More ficed. The implanted TEVAs were examined both grossly and immunohistologically. The implanted TEVAs showed no evidence of stenosis or dilatation. No thrombus was found inside the TEVAs. even without any anticoagulation therapy. Remnants of the polymer scaffolds weie not observed in all specimens, and the overall gross appearance appeared similar to that of native IVCs. Inimunohistological staining revealed the presence of Factor VIII positive nudcated cells at the luminal surface of the TEVAs. In addition, lesions were observed where α-smooth muscle actin and desmin positive cells existed. Implanted TEVAs contained a sufficient aniotnit of extracellular matrix, and showed neither occlusion nor anetuysmal formation. In addition. endothelial cells were found to line the luminal surface of each TEVA. These results strongly suggest that 'ideal' venous grafts with anti-thrombogenicity can be produced. Using theTEtedmique, a peripheral pulmonary artery was successfully reconstructed in a 4 year-old girl using autologous venous cells. The occluded pulmonary artery was reconstructed with the TEvessel graft No postojemtive complications occurred On follow-up angiography, the transplanted vessels were noted to be completely patent. In the same manner, autologous pericardium using biodegadable polymer sheet was examined in an animal model. Pericardial adhesion was relatively mild companing to the prosthetic materials. Because both our laboratory and clinical experiences are quite encouraging, we suggest that the TE approach may play an important ole as an alternative metohd to transplantation and to the use of artificial organs in the fldd of pediatric cardiovasucular surgery. Less