Department of Cardiovascular Surgery, Christian-Albrechts-University of Kiel, School of Medicine, Kiel, Germany.
Ann Thorac Surg. 2010 Jan;89(1):259-63. doi: 10.1016/j.athoracsur.2009.06.048.
The purpose of this study was to evaluate the feasibility of percutaneously implanted tissue-engineered valved stents in the ovine pulmonary valve position.
Porcine pulmonary heart valves and small intestinal submucosa were obtained from a slaughterhouse, and the intestinal submucosa used to cover the inside of the porcine pulmonary valved stents. Endothelial cells and autologous myofibroblasts were obtained from carotid artery segments of juvenile sheep. After myofibroblast seeding, constructs were placed in a dynamic bioreactor system and were cultured for 16 days. After Endothelial cell seeding, the tissue-engineered valved stents were deployed into the pulmonary valve annular site. Angiography was performed at implantation and explantation (4 weeks). Constructs were analyzed macroscopically and microscopically.
Orthotopic positioning of the stents (n = 3) at the time of implantation and explantation, as well as normal valve function, was observed through angiography. Gross morphology confirmed excellent opening and closing of all leaflets. Strong expression of alpha-smooth muscle actin in neointerstitial cells and of von-Willebrand-Factor in endothelial cells was revealed by immunocytochemistry.
This study demonstrates successful merging of two novel technologies: (1) percutaneous valved stent implantation and (2) tissue engineering of autologous heart valves.
本研究旨在评估经皮植入组织工程化瓣状支架在羊肺动脉瓣位置的可行性。
从屠宰场获得猪肺动脉瓣和小肠黏膜下层，并将肠黏膜下层用于覆盖猪肺动脉瓣状支架的内部。从幼年绵羊的颈动脉段获得内皮细胞和自体成纤维细胞。在成纤维细胞接种后，将构建体放置在动态生物反应器系统中培养 16 天。内皮细胞接种后，将组织工程化瓣状支架部署到肺动脉瓣环部位。在植入和取出时（4 周）进行血管造影。通过大体和显微镜分析来评估构建体。
通过血管造影观察到支架在植入和取出时的原位定位（n = 3），以及正常的瓣膜功能。大体形态学证实了所有瓣叶的良好开闭。免疫细胞化学显示，新的间质细胞中α-平滑肌肌动蛋白的表达强烈，内皮细胞中 von-Willebrand-Factor 的表达强烈。
本研究成功地融合了两项新技术：（1）经皮瓣状支架植入术和（2）自体心脏瓣膜的组织工程化。
