Schubert Kathrin, Schaller Tim, Stojenthin Elisabeth, Stephan Christian, Sievers Hans-Hinrich, Scharfschwerdt Michael
Department of Cardiac and Thoracic Vascular Surgery, University of Luebeck, Luebeck, Germany.
Interact Cardiovasc Thorac Surg. 2019 May 1;28(5):689-694. doi: 10.1093/icvts/ivy337.
Heart valve prostheses are the therapy of choice for patients with severe heart valve diseases. Two types of prostheses that can be implanted in patients are available: biological and mechanical. Though mechanical heart valves have some disadvantages like necessity of life-long anticoagulation, biological heart valve prostheses often necessitate reinterventions due to limited durability. Therefore, a new trileaflet mechanical heart valve was developed, featuring hinges in the systolic flow with the aim of function and thrombogenicity.
We first compared the new trileaflet mechanical heart valve to conventional bileaflet heart valves (St. Jude Medical and On-X valves) in vitro. Haemodynamic measurements were performed in a pulse duplicator system, and clot formation was examined with an implemented method using enzyme-activated milk as the test medium.
Haemodynamic measurements showed the largest effective orifice areas and smallest pressure gradients for the trileaflet prosthesis compared to the bileaflet valve. Opening and closing characteristics of the trileaflet valve and of the St. Jude Medical valve were comparable. Clotting tests depicted only minor isolated deposits for the new trileaflet valve whereas the bileaflet valves showed distinct clots in the area of the hinge in all experiments.
Haemodynamic and clotting tests showed improvements for the new trileaflet valve compared to common bileaflet valves. The off-wall systolic position of the hinges, which eluded adverse flow areas, was a major advantage of the new valve.
心脏瓣膜假体是重症心脏瓣膜疾病患者的首选治疗方法。可植入患者体内的假体有两种类型：生物瓣膜和机械瓣膜。尽管机械心脏瓣膜存在一些缺点，如需要终身抗凝，但生物心脏瓣膜假体由于耐久性有限，常常需要再次干预。因此，研发了一种新型三叶机械心脏瓣膜，其特点是在收缩期血流中有铰链，目的在于改善功能和血栓形成倾向。
我们首先在体外将新型三叶机械心脏瓣膜与传统双叶心脏瓣膜（圣犹达医疗公司瓣膜和On-X瓣膜）进行比较。在脉搏复制系统中进行血流动力学测量，并使用以酶激活牛奶为测试介质的既定方法检查血栓形成情况。
血流动力学测量结果显示，与双叶瓣膜相比，三叶瓣膜假体的有效瓣口面积最大，压力梯度最小。三叶瓣膜和圣犹达医疗公司瓣膜的开闭特性相当。凝血测试表明，新型三叶瓣膜仅出现少量孤立的沉积物，而在所有实验中，双叶瓣膜在铰链区域均出现明显血栓。
与普通双叶瓣膜相比，血流动力学和凝血测试表明新型三叶瓣膜有所改进。铰链在收缩期处于离壁位置，避开了不利的血流区域，这是新型瓣膜的一个主要优点。
