用于主动脉返流的纳米涂层带可降解冠状动脉主动脉瓣膜支架的研究

Presently, the principal treatment for aortic disease is still aortic valve replacement under CPB (cardiopulmonary bypass). But a part of senile patients with severe disease can not bear the shock of operation. Rencently transcatheter aortic valve implantation offers another selective therapeutic method, and several products are applied in clinic tentatively. Most of the present aortic valved stents are designed for aortic stenosis, some problems need to be resolved, such as effective fixing, effects on coronary artery flow, perivalvular leakage and so on. Domestic research work on aortic valved stent was rare. Our research team began this work in an early period. We have manufactured a new aortic valved stent in the shape of aortic root, and feasibility of transcatheter implantation in pig's heart has been proved by animal experiments. Some problems about the new aortic valved stent were exposed, such as moderate aortic regurgitation was exist too. In present research, the individual specific aortic valved stent will be manufactured. we'll design and manufacture degradable coronary artery stent riveted to aortic valved stent, which can assure smooth blood flow of coronary artery and improve the positioning ability. Riveted degradable coronary artery stent can make the stent more adherent to aortic wall, which will prevent dissection of aorta and aortic regurgitation.Ivalon will be sutured around the ring to reduce aortic regurgitation. Ivalon was the research findings of previous National Natural Science Foundation.The physical and chemical characteristics of new aortic valved stent will be optimized by Ti/TiN nano coating technology, and the suturing technology of artificial bovine valve will be ameliorated. Besides, the positioning mark and related delivery system need to be designed.

目前治疗主动脉瓣膜疾病方法仍是在体外循环下行瓣置换术，但高龄或合并严重疾病的患者死亡率和并发症高，经导管主动脉瓣膜植入（TAVI）提供了一种可选择的治疗手段，国外初步应用于临床，但目前主要适用于钙化主动脉瓣膜狭窄的患者，同时存在一些问题尚未解决，如有效固定、对冠脉血流的影响、瓣周漏等。国内有关TAVI的研究较少。本课题组较早开展主动脉瓣膜支架的研制，根据主动脉根部形态已设计制作出了针对主动脉瓣疾病的新型主动脉瓣膜支架，通过体内动物实验证实该主动脉瓣膜支架可经导管体内植入，但瓣膜支架植入后同样存在返流。本研究拟设计制作个体化主动脉瓣膜支架，并设计与之铆定的左右冠脉可降解支架，正确固定，确保冠脉血流通畅，同时使支架更加贴壁，防止夹层和返流。根据前国家自然基金研究成果Ivalon包裹瓣环，促进内皮生长，可解决瓣周漏；结合纳米结构Ti/TiN涂层，提高支架的组织相容性，可解决存在的不足。

经导管主动脉瓣膜植入（TAVI）已应用于临床，但主要适用于钙化主动脉瓣膜狭窄的患者，同时存在一些问题尚未解决。本课题组较早开展主动脉瓣膜支架的研制，在本课题的资助下 根据主动脉根部形态已设计制作出了针对主动脉瓣疾病的新型主动脉瓣膜支架，通过Ivalon包裹瓣环，结合纳米结构Ti/TiN涂层，提高支架的组织相容性；本课题同时改进、研制出了可用于主动脉内瓣膜支架体外流体力学性能测试的装置；新型瓣膜支架经物理机械性能、流体力学及生物相容性等体外实验明确支架具有较好的体外特性，并经体内动物实验证实该主动脉瓣膜支架可经导管体内植入，但瓣膜支架植入后仍存在轻度的瓣膜返流及瓣周漏。课题同时开展了左右冠状动脉窦处铆钉状左右冠状动脉支架的设计；编织了左右冠状动脉窦处铆钉状的左右冠状动脉支架。在课题的支持下发表文章2篇，申请专利2项，其中授权实用新型专利1项，或发明奖获省部级发明奖5项。