经心尖导管植入自膨胀式主动脉瓣支架动物实验

 目的  探讨开胸穿刺经心尖导管植入国产自膨胀式带瓣膜支架置换动物主动脉瓣的可行性和有效性。方法  自主设计酒杯状镍钛合金自膨胀支架,将新鲜的猪心包经脱细胞、防钙化等处理后裁剪成人工瓣膜,缝合在支架上,制成自膨胀式带瓣膜主动脉支架。选择健康羊8只,左侧开胸小切口暴露心尖,穿刺左心室心尖,送入加硬钢丝经左心室-升主动脉-降主动脉建立轨道,透视引导下沿加硬钢丝通过18F输送鞘管将自膨胀式带瓣膜支架送至羊主动脉瓣位置,确认正确定位后退出输送鞘管释放支架,置换动物原主动脉瓣。手术后即刻行超声和血管造影检查瓣膜工作情况。结果  1只羊因支架植入位置过高导致冠状动脉堵塞当场死亡;1只羊因为术中支架置入位置过低导致主动脉瓣大量瓣周漏,术后死亡;余6只实验羊经导管瓣膜置换术均获得成功,术后即时DSA影像、超声检查结果表明人工主动脉瓣膜植入位置理想,无明显反流及瓣周漏,人工瓣膜代替原瓣膜工作正常。结论  使用国产自膨胀式带瓣膜支架及其输送系统通过经心尖途径经导管植入置换动物主动脉瓣方法可行、有效。

Transcatheter transapical aortic valve implantation with a self-expanding valve stent:an experimental study

Objective  To evaluate the feasibility and effectiveness of transcatheter transapical implantation of a new-type domestic self-expanding valved stent into the aortic valve position of goats.Methods  We designed a new cup-like self-expanding nitinol valved stent.Fresh porcine pericardium was treated with cell extracting and anti-calcification,the treated porcine pericardium was trimmed into artificial leaflets and sutured into the nitinol alloy stent by hand.Eight goats were used.A left anterolateral minithoracotomy was performed.After opening the pericardium,the apex of the left ventricle was punctured,a stiff guidewire was positioned across the aortic arch and anchored in the descending aorta.The delivery catheter (18F) was then introduced through the stiff guidewire into the aorta arch under fluoroscopic guidance.After correct valve position was confirmed by digital subtration angiography,the catheter was withdrawed slowly and the valved stent was released.The immediate function outcome  of valved stents was evaluated with angiography and echocardiography after implantation.Results  Six devices were successfully implanted into aortic valve position of goats.One goat died of acute myocardial infarction because the valved stent was implanted higher than the normal position and the ostia of the coronary artery was occluded.Another goat died of severe aortic valve regurgitation because the valved stent was implanted below the normal position.Immediate observation after the procedure showed that the valved stents were in the desired position after implantation by angiography,echocardiogram and anatomy.No moderate to severe aortic regurgitation was observed.The artificial valve worked well after it replaced the origiral valve.Conclusions  The proceduce of transcatheter transapical aotic valve implantation using the new type domestic self expanding valved stent and delivery system were feasible and effective.