液氮冷冻保存同种瓣膜临床使用现状

同种瓣膜在心脏外科使用越来越频繁，被用于右心室和左心室流出道重建，也被用于三尖瓣，二尖瓣替换。但是同种主动脉用于肺动脉瓣替换和同种肺动脉用于高压动脉血管血管替换的耐久性较差。其优点为优良的血流动力学特性，无需抗凝治疗和血栓栓塞并发症发生率低。但取材限制和远期狭窄问题使其使用受到限制。同种瓣膜的进行性狭窄被认为与低水平的免疫反应有关。

Current Status of Valve Homografts Cryopreserved in Liquid Nitrogen

The application of valve homografts are more frequently in cardiac surgery to reconstruct of the right or left ventricular outflow tract. Now they have been adopted for replacement of mitral valve and tricuspid valve homografts,but they are less durable in high pressure site. There are excellent hemodynamic characteristics in homograft eg. no need for adminitration of anticoagulation, and thromboembolic problems. However, it is concerned that the valve homografts may develop stenosis in long term resulted from low-grade immune reactions. Even as the biological valve grafts become more popular,but it can cause late stenosis and the shortages of donor graft will limit their use.