In vitro study of coronary flow occlusion in transcatheter aortic valve implantation.
In vitro study of coronary flow occlusion in transcatheter aortic valve implantation.
复制标题
经导管主动脉瓣植入中冠状动脉血流阻塞的体外研究。
作者：
Zheng;Wei;G. Lutter;R. Quaden;J. Cremer;Xiu
背景
经导管主动脉瓣植入术（TAVI）是近年来发展起来的一种用于高发病率患者和被认为不能耐受标准外科主动脉瓣置换术的患者的方法。然而，TAVI与并发症相关，如冠状动脉口潜在阻塞、二尖瓣关闭不全和支架移位，尽管它似乎很有希望。TAVI后冠状动脉血流受损是灾难性的，并且被认为与冠状动脉口和主动脉瓣叶和瓣膜支架的闭合位置有关。然而，关于瓣膜支架与主动脉根部解剖结构（包括冠状动脉口、主动脉瓣叶）之间的解剖关系的数据很少。
方法
对40例心脏标本的主动脉根部进行了观察。测量主动脉瓣宽度、主动脉窦环至窦管交界处（STJ）高度、主动脉窦环至相应冠状动脉口距离、冠状动脉口至相应STJ水平距离。分别评价支架置入前后及主动脉开放后瓣膜支架、主动脉瓣叶及冠状动脉口的关系。
结果
大约四分之三的冠状动脉口位于STJ水平以下。左、右和后主动脉窦环到相关STJ水平的平均距离相当，分别为18.5±2.7、18.9±2.6、18.7±2.6 mm。左、右主动脉窦环距冠状动脉口的高度分别为（16.6±2.8）mm和（17.2±3.1）mm。
结论
冠状动脉口大多位于STJ水平以下，可被瓣叶覆盖。这强调了改良支架的必要性，以防止TAVI后冠状动脉血流闭塞。
BACKGROUND
Transcatheter aortic valve implantation (TAVI) has been developed recently for patients with high morbidities and who are believed to be not tolerate standard surgical aortic valve replacement. Nevertheless, the TAVI is associated with complications such as potential obstruction of coronary ostia, mitral valve insufficiency, and stent migration although it seems promising. Impairment of the coronary blood flow after TAVI is catastrophic and it was believed to be associated with the close position of the coronary orifice and the aortic leaflets and valve stent. However, few data was available as to the anatomic relationship between valve stent and aortic root anatomic structures including the coronary arterial ostia, aortic leaflets.
METHODS
The aortic roots were observed in 40 hearts specimens. The width of aortic leaflet, height of aortic sinus annulus to the sinutubular junction (STJ), distance between aortic sinus annulus to its corresponding coronary ostia, and coronary arterial ostia to its corresponding STJ level were measured. Moreover, the relationships of valve stent, aortic leaflets and coronary ostia before/post stent implantation and after the open of aorta were evaluated respectively.
RESULTS
Approximate three quarters of the coronary ostia were located below the STJ level. The mean distances from left, right and posterior aortic sinus annulus to the related STJ level was comparable, which was 18.5±2.7, 18.9±2.6, 18.7±2.6 mm, respectively. Meanwhile, the height of left and right aortic sinus annulus to its corresponding coronary ostia was 16.6±2.8 and 17.2±3.1 mm for left and right side respectively.
CONCLUSIONS
Most of the coronary ostia were located below the STJ level and could be covered by the leaflets. This highlights the need of modified stents to prevent occlusion of coronary flow after TAVI.