Background Percutaneous aortic valve replacement is a promising strategy in the treatment of patients with aortic valve stenosis. And many kinds of valved stents have been implanted in selected patients worldwide. How...Background Percutaneous aortic valve replacement is a promising strategy in the treatment of patients with aortic valve stenosis. And many kinds of valved stents have been implanted in selected patients worldwide. However, the clinical experience is still limited. We developed a W-model valved stent and evaluated the feasibility and safety of percutaneous implantation of the device in the native aortic valve position.Methods A self expanding nitinol stent with W-model, containing porcine pericardium valves in its proximal part, was implanted in six sheep by means of a 14 French catheter through the right common iliac artery under guidance of fluoroscopy. During stent deployment the original aortic valve was pushed against the aortic wall by the self expanding force of the stent while the new valve was expanded. These sheep were followed up shortly after procedure with supra-aortic angiogram and left ventriculography. Additionally, one sheep was sacrificed after the procedure for anatomic evaluation.Results It was possible to replace the aortic valve in the beating heart in four sheep. The procedure failed in two sheep due to coronary orifice occlusion in one case and severe aortic valve regurgitation in the other case. One sheep was killed one hour after percutaneous aortic valve replacement for anatomic evaluation. There were no signs of damage of the aortic JntJma, or of obstruction of the coronary orifice,Conclusions Percutaneous aortic valve replacement with a W-model valved stent in the beating heart is possible. Further studies are mandatory to assess safety and efficacy of this kind of valved stent in larger sample size and by longer follow-up period.展开更多
背景:由于骨质原因及结构特点导致椎弓根螺钉经常出现把持力下降,从而发生松动、拔出,导致内固定失败,因此提高椎弓根螺钉的稳定性显得尤为重要。目的:检测可注射骨水泥空心椎弓根螺钉椎弓根螺钉生物力学稳定性,为优化骨水泥使用量提供...背景:由于骨质原因及结构特点导致椎弓根螺钉经常出现把持力下降,从而发生松动、拔出,导致内固定失败,因此提高椎弓根螺钉的稳定性显得尤为重要。目的:检测可注射骨水泥空心椎弓根螺钉椎弓根螺钉生物力学稳定性,为优化骨水泥使用量提供参考。方法:选取7具新鲜成人尸体T11-L4椎体标本共40个椎体,随机分为可注射骨水泥空心椎弓根螺钉及DTPS TM椎弓根螺钉组,各20个,置钉后分别注入1,2,3,5 m L骨水泥,通过影像学观察骨水泥弥散分布情况,并测得最大轴向拔出力进行比较。结果与结论:骨水泥用量为1-3 m L时,可注射骨水泥空心椎弓根螺钉组螺钉平均最大轴向拔出力显著高于DTPS TM组(P<0.05)。骨水泥用量为5 m L时,2组平均最大轴向拔出力差异无显著性意义(P>0.05)。可注射骨水泥空心椎弓根螺钉组的直线回归方程为Y=25.269X+133.681(R2=0.837),DTPS TM椎弓根螺钉组的直线回归方程为Y=32.039X+99.251(R2=0.936)。骨水泥用量在1-5 m L时,2组螺钉最大轴向拔出力与骨水泥量高度正相关(|R|>0.8)。说明骨水泥强化椎弓根螺钉可显著提高螺钉稳定性,椎弓根螺钉最大轴向拔出力与骨水泥使用量呈高度正相关,可注射骨水泥空心椎弓根螺钉在达到满意的内固定强化效果同时,减少骨水泥使用量,降低了骨水泥泄漏风险,相比DTPS TM椎弓根螺钉更具有优势。展开更多
文摘Background Percutaneous aortic valve replacement is a promising strategy in the treatment of patients with aortic valve stenosis. And many kinds of valved stents have been implanted in selected patients worldwide. However, the clinical experience is still limited. We developed a W-model valved stent and evaluated the feasibility and safety of percutaneous implantation of the device in the native aortic valve position.Methods A self expanding nitinol stent with W-model, containing porcine pericardium valves in its proximal part, was implanted in six sheep by means of a 14 French catheter through the right common iliac artery under guidance of fluoroscopy. During stent deployment the original aortic valve was pushed against the aortic wall by the self expanding force of the stent while the new valve was expanded. These sheep were followed up shortly after procedure with supra-aortic angiogram and left ventriculography. Additionally, one sheep was sacrificed after the procedure for anatomic evaluation.Results It was possible to replace the aortic valve in the beating heart in four sheep. The procedure failed in two sheep due to coronary orifice occlusion in one case and severe aortic valve regurgitation in the other case. One sheep was killed one hour after percutaneous aortic valve replacement for anatomic evaluation. There were no signs of damage of the aortic JntJma, or of obstruction of the coronary orifice,Conclusions Percutaneous aortic valve replacement with a W-model valved stent in the beating heart is possible. Further studies are mandatory to assess safety and efficacy of this kind of valved stent in larger sample size and by longer follow-up period.
文摘背景:由于骨质原因及结构特点导致椎弓根螺钉经常出现把持力下降,从而发生松动、拔出,导致内固定失败,因此提高椎弓根螺钉的稳定性显得尤为重要。目的:检测可注射骨水泥空心椎弓根螺钉椎弓根螺钉生物力学稳定性,为优化骨水泥使用量提供参考。方法:选取7具新鲜成人尸体T11-L4椎体标本共40个椎体,随机分为可注射骨水泥空心椎弓根螺钉及DTPS TM椎弓根螺钉组,各20个,置钉后分别注入1,2,3,5 m L骨水泥,通过影像学观察骨水泥弥散分布情况,并测得最大轴向拔出力进行比较。结果与结论:骨水泥用量为1-3 m L时,可注射骨水泥空心椎弓根螺钉组螺钉平均最大轴向拔出力显著高于DTPS TM组(P<0.05)。骨水泥用量为5 m L时,2组平均最大轴向拔出力差异无显著性意义(P>0.05)。可注射骨水泥空心椎弓根螺钉组的直线回归方程为Y=25.269X+133.681(R2=0.837),DTPS TM椎弓根螺钉组的直线回归方程为Y=32.039X+99.251(R2=0.936)。骨水泥用量在1-5 m L时,2组螺钉最大轴向拔出力与骨水泥量高度正相关(|R|>0.8)。说明骨水泥强化椎弓根螺钉可显著提高螺钉稳定性,椎弓根螺钉最大轴向拔出力与骨水泥使用量呈高度正相关,可注射骨水泥空心椎弓根螺钉在达到满意的内固定强化效果同时,减少骨水泥使用量,降低了骨水泥泄漏风险,相比DTPS TM椎弓根螺钉更具有优势。
