Biomechanical comparison of human pulmonary and aortic roots
Biomechanical comparison of human pulmonary and aortic roots
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DOI：
10.1093/ejcts/ezr163
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发表时间：
2012-05-01
影响因子：
3.4
通讯作者：
Tseng, Elaine E.
中科院分区：
文献类型：
--
作者：
Azadani, Ali N.;Chitsaz, Sam;Tseng, Elaine E.
Ross手术后自体肺移植物的显著扩张是有问题的，可能需要再次手术。肺自体移植物重塑发生在对压力和随后的壁应力的立即升高的响应中。肺根的应力应变反应在理解自体移植物功能和Ross手术后的重建中起着重要作用。然而，有限的数据是可用的新鲜人肺根的机械性能。本研究的目的是比较Ross手术前新鲜人肺动脉和主动脉根部的机械性能。新鲜健康人心脏（n = 21）从加州移植供体网络（Oakland，CA，USA）获得。五个区域的肺动脉和主动脉根，前动脉和后动脉和三个窦，进行位移控制的双轴拉伸试验在24小时内的交叉夹紧时间。基于体循环压力下的组织硬度，使用配对比较方法对肺动脉根和主动脉根的不同区域进行比较。此外，组织学分析，比较肺和主动脉根的纤维结构。人肺和主动脉根表现出非线性响应的双轴载荷在圆周和纵向方向。在体循环压力下，肺动脉在两个主要方向上的刚性均显著高于升主动脉（P < 0.001）。同样地，在两个方向上，在体循环压力下，肺静脉窦比主动脉窦更硬（P < 0.001）。组织学分析显示，主动脉根弹性蛋白编织紧密，肺动脉根与主动脉根弹性蛋白编织紧密，肺这些区域差异可能影响肺自体移植物重塑和影响晚期自体移植物扩张。
Significant dilation of the pulmonary autograft is problematic after the Ross operation and may require reoperation. Pulmonary autograft remodelling occurs in response to the immediate rise in pressure and consequently wall stress. Stress-strain response of the pulmonary root plays an important role in understanding autograft function and remodelling following the Ross procedure. However, limited data are available on mechanical properties of fresh human pulmonary roots. The aim of this study was to compare mechanical properties of fresh human pulmonary and aortic roots prior to the Ross operation.Fresh healthy human hearts (n = 21) were obtained from California Transplant Donor Network (Oakland, CA, USA). Five regions of pulmonary and aortic roots, anterior and posterior artery and three sinuses, were subjected to displacement-controlled equibiaxial stretch testing within 24 h of cross-clamp time. Different regions of pulmonary and aortic roots were compared using a paired-comparison approach based on tissue stiffness at systemic pressure. Furthermore, histologic analysis was performed to compare the fibrous structure of pulmonary and aortic roots.Human pulmonary and aortic roots demonstrated nonlinear response to biaxial loading in both circumferential and longitudinal directions. Pulmonary artery was found to be significantly stiffer than ascending aorta at systemic pressure in the two principal directions (P < 0.001). Similarly, pulmonary sinuses were significantly stiffer than the aortic sinuses at systemic pressure in the two directions (P < 0.001). Histological analysis revealed that aortic roots had tight denser weave of elastin than pulmonary roots.Significant differences were found in the compliance and fibrous structure of human pulmonary and aortic roots. These regional differences may impact pulmonary autograft remodelling and influence late autograft dilation.