一种新型的压差介导开窗式主动脉腔内移植物系统的实验研究

背景：近年，主动脉腔内隔绝术的挑战是如何通过完全腔内治疗的方式处理累及分支动脉的病变主动脉，虽然许多新型腔内移植物产品已经应用于临床且早期疗效肯定，但是，这些新产品不仅需要对主动脉及其重要分支进行严格的术前影像评估，如近端锚定区，病变和分支动脉的精确测量，而且需要时间为患者量身定制腔内移植物。因此，限制了微创治疗主动脉病变的应用范围。为解决这一难题，本研究设计一种新型腔内移植物系统，通过主动脉与分支动脉间的压力差，诱发移植物的覆膜自动“开窗”，并到达保存分支，减少并发症的目的。 方法：选用实验猪12头（雄性8头，雌性4头），压力传感器同步测量覆膜支架封堵分支前后，左锁骨下动脉与主动脉弓间的血压差大小及变化情况。根据动物体内测的压力差大小，通过多重纺织成型技术试制能在该压力差诱导下出现覆膜变形和渗漏的新型移植物覆膜，即多重纺织密度人造覆膜（MDPM）。将MDPM缝合到直管型覆膜支架上制成移植物样品，在体外模型内测试其压力变形和渗漏能力。 结果：12头猪全部成功植入管型腔内覆膜支架封堵左锁骨下动脉并成功测压，猪左锁骨下动脉被管型腔内覆膜支架完全封闭后，主动脉弓血压比左锁骨下动脉血压高42.78±5.17mmHg（P<0.001）。将此种覆膜整合到普通直管型主动脉覆膜支架，操作简单易行，移植物系统且易于导入和准确定位释放。当MDPM两侧压力接近40mmHg，LSA分支出口处可见明显造影剂漏出。 结论：首次提出压差介导开窗式主动脉腔内移植物系统的设计，也许能为主动脉腔内修补术开创一种新的思路。关于压差介导开窗式主动脉腔内移植物系统在活体内的可行性有待进一步研究。

A Novel Pressure Difference Induced-perforation Aortic Stent-grafts System: An Experimental Study

Background Most of endovascular stent-graft modifications to preserve side branch must be customized according to extensive pre-operative assessment,which may not be possible in many hospitals and emergency settings.The study was to develop a novel stent-grafts system that would allow in situ “fenestration”,with less reliance on preoperative imaging.Methods The magnitude of pressure difference (PD) between left subclavian artery (LSA) and aortic arch were measured in 12 experimental pigs.Changes of PD before and after LSA was covered were analyzed respectively.The novel stent graft was made by multi-dimensional and multiple textiles forming technology.According to the PD measurement in pigs,we evaluated the feasibility of the stent-graft in a mock circulation system.Results In pigs,the blood pressure of aortic arch was significantly higher than that of LSA after it was covered (P ＜0.001) and PD was (42.78±5.17) mmHg.After target vessel was covered and when PD between the LSA and aorta reached the magnitude measured in pigs,contrast media oozed from the cranny of graft to the LSA,which was generated by sliding and deformation of yarns of novel stent-graft.Conclusions The study proposes the design of pressure difference-induced perforation aortic stent-grafts system and verifies that the PD between LSA and aortic arch is high enough to allow in situ “fenestration” by stent graft made by multi-dimensional and multiple textiles forming technology.