Development of intra-aortic stent inserted percutaneously for aeute dissection

本课题的研究目的是研制一种能在降主动脉夹层中永久性植入并促进血栓形成的主动脉内支架。在传统的动物模型中，主动脉夹层由于其栓塞性阻塞，只有一个夹层入口，因此具有高度自发性恢复的趋势。然后，在本实验中，我们在主动脉夹层上进行了进入和再进入，并观察了该模型的长期过程超过2年。结果是显著的：在此动物模型上，我们植入了血管内支架。然而，为了防止移植物迁移，支架必须强烈地按压主动脉壁。在如此强大的压力下，脆弱的主动脉很容易破裂。这是一个矛盾的困境，为了解决这个困境，我们开发了一种新的圆柱形球囊暂时阻塞假腔。在降主动脉夹层模型中应用新型圆柱形球囊。当我们充盈球囊时，假腔的入口关闭。用超声回声仪评价真腔和假腔的血流。目前的结果表明，当我们用我们的新球囊阻塞入口至少6小时时，假腔与血栓一起完全塌陷。因此，该方法有望成为治疗急性降主动脉夹层的一种划时代的临床治疗方法。据此我们继续研究，试图临床应用.

Development of intra-aortic stent for acute dissection in the descending aorta, which is designed to be percutaneously inserted and to promote the thrombus formation in the pseudolumen, is the goal of this project.At the start, we tried to make novel animal model of aortic dissection at the descending aorta. In conventional animal models, aortic dissection has a tendency of high spontaneous recovery due to its embolic obstruction, because it has only an entry of the dissection. Then, in the present experiment, we made both entry and re-entry on the aortic dissection and observed the long term course of this model more than 2 years. The result was remarkable : the patency of the pseudo-lumen on new method was 100% in the aorta.On this animal model, we implanted an intravascular stent percutaneously. In order to prevent graft migration, however, a stent must be press the aortic wall strongly. With such strong pressure, the weak aortic is easy to rupture. .This is a contradicing dilemma.In order to solve this dilemma, we develop an new cylindrical balloon to obstruct temporally the pseudo lumen. We applied new cylindrical balloon in the aortic dissection model of the descending aorta. When we inflate the balloon, the entry of the pseudo-lumen close. The evaluation of the blood flow of the true lumen and the false-lumen was carried out with a ultrasonic echograph. The present result indicated that when we obstruct the entry with our new balloon at least 6 hours, the false lumen collapse completely with the thrombus. Thus this method is promising for the treatment of the acute dissection of descending aorta, as a epoch-making clinical treatment method. Accordingly we continue to study in an attempt to clinical application.