Development of new stent made of the composite of medical polymer and shape memory allow.

设计了一种新的支架，以防止呼吸道坍塌。将钛镍形状记忆合金与医用聚合物复合制成新型支架。支架的结构设计类似于天然气管，即具有横向外观的软管鞋形的管子。为了不将金属合金直接附着在宿主组织上，支架上覆盖了医用级硅胶。在原计划中，我们打算使用新型形状记忆丝来制作新的支架。然而，由于关西大地震，我们的研究伙伴神户制钢公司在神户的研究中心于1995年1月17日被完全摧毁。工厂以及数据和材料都被淘汰了。大约花了半年的时间才恢复了制造形状记忆合金的系统。尽管有这些困难，我们还是用金属铸件制造了支架钢丝管。用直径为0.5 mm的钛镍丝制作了支架管的块状结构。然后，我们将内侧的硅胶片与尼龙网加固的硅橡胶结合在一起。里面的硅胶片的目的是为了促进呼吸道分泌物的排出。这种新研制的支架被应用于预防犬呼吸道塌陷。动物实验始于1996年1月。到目前为止，我们在12只比格犬身上植入了支架，因为它的气管事先被破坏了，所以它们变成了气管软化。所有狗植入后的临床过程都是顺利的。研究结果发表在东京举行的日本胸外科协会年会上。由于我们的支架使用的是金属材料，临床上患者被认为是暴露在MRI条件下。因此，为了确定支架在这种情况下的安全性，我们在MRI检查中对金属的安全性进行了研究，并在期刊上进行了报道。

New stent was designed to prevent the collapse of the air way. New stent was made from the composite of Ti-Ni shape memory alloy and medical polymer. The structure of the stent was designed to resembling to that of the native trachea, namely it is a tube with a transverse appearance hose shoe shape. In order not to attach the metallic alloy directly to the host tissue, the stent was covered with medical grade silicone.In the original plan, we intended to make new stent using the novel shape memory wire. However, because of the Big Earthquake in Kansai, the research center of the our research partner Kobe Steel Company in Kobe was destroyed completely on 17th January 1995. The plant as well as the data and material became out of use. It took about half year to recover the system to make the shape memory alloy. In spite of these difficulties, we made a metallic cast of manufacture the stent wire tube. Using the Ti-Ni wire with a diameter of 0.5 mm, balk structure of the stent tube was made. Then, we combined the silicone sheet inside on this balk with the silicone rubber reinforced with nylon mesh. The aim of the silicone sheet inside is to facilitate the drainage of the secretion of the airway. This newly developed stent was applied to the prevention from the airway collapse in dogs. Animal experiment began in January 1996. Until now, we implanted the stent in 12 beagle dog, whose trachea was previously destroyed in advance, so as they became the tracheomalacia. The clinical course after the implantation was uneventful in all dog. The results are reported on the annual meeting of Japanese Association for Thoracic Surgery in Kyoto.Because our stent use the metallic material, in clinically patients are considered to be exposed the MRI condition. Therefore, in order to confirm the safety of the stent in such condition, we study the safety of the metal at the MRI examination and reported it on a journal.