On the in vivo deformation of the mitral valve anterior leaflet: effects of annular geometry and referential configuration.
On the in vivo deformation of the mitral valve anterior leaflet: effects of annular geometry and referential configuration.
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DOI：
10.1007/s10439-012-0524-5
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发表时间：
2012-07
影响因子：
3.8
通讯作者：
Sacks, Michael S.
中科院分区：
文献类型：
--
作者：
Amini, Rouzbeh;Eckert, Chad E.;Koomalsingh, Kevin;McGarvey, Jeremy;Minakawa, Masahito;Gorman, Joseph H.;Gorman, Robert C.;Sacks, Michael S.
据推测，天然二尖瓣 (MV) 形状的改变对局部组织应力分布具有深远影响，并且可能与修复耐久性的限制有关。本研究的目的是在绵羊模型中使用扁平瓣环成形术来阐明二尖瓣环形状与中央二尖瓣前叶 (MVAL) 应变历史之间的关系。此外，我们首次报告体内残留的小叶菌株的存在。使用缝合到 MVAL (n=10) 的声晶体换能器测量体内小叶变形，并在整个心动周期内获取 3D 位置。在六只动物中，将扁平环缝合到环上并记录换能器位置，而在其余四只动物中，从放血的心脏中切除MV并获得无应力换能器位置。在 MVAL 的中心区域，参考最小左心室压力 (LVP) 的峰值拉伸值在圆周方向和径向方向上分别为 1.10 ± 0.01 和 1.31 ± 0.03（平均值 ± 标准误差）。平环瓣环成形术后，在最小LVP时，中央MVAL环向收缩28％，径向拉长16％，并且在整个心动周期中环向处于负应变状态。从放血的心脏切除瓣膜后，MVAL 显着收缩（周向和径向分别为 18% 和 30%），表明体内存在大量残余应变。虽然残余应变（及其相关应力）的生理功能目前尚不清楚，但对于 MV 功能的精确计算模拟来说，考虑它们的存在显然是必要的。此外，我们证明环形几何形状的变化会显着改变体内瓣膜功能应变。由于稳态应变水平与组织重塑和稳态有关，我们的结果表明，手术引起的 MV 形状改变可能会导致长期 MV 力学生物学和微观结构改变，最终影响 MV 修复耐久性。
Alteration of the native mitral valve (MV) shape has been hypothesized to have a profound effect on the local tissue stress distribution, and is potentially linked to limitations in repair durability. The present study was undertaken to elucidate the relation between MV annular shape and central mitral valve anterior leaflet (MVAL) strain history, using flat annuloplasty in an ovine model. In addition, we report for the first time the presence of residual in-vivo leaflet strains. In-vivo leaflet deformations were measured using sonocrystal transducers sutured to the MVAL (n=10), with the 3D positions acquired over the full cardiac cycle. In six animals a flat ring was sutured to the annulus and the transducer positions recorded, while in the remaining four the MV was excised from the exsanguinated heart and the stress-free transducer positions obtained. In the central region of the MVAL the peak stretch values, referenced to the minimum left ventricular pressure (LVP), were 1.10 ± 0.01 and 1.31 ± 0.03 (mean ± standard error) in the circumferential and radial directions, respectively. Following flat ring annuloplasty, the central MVAL contracted 28% circumferentially and elongated 16% radially at minimum LVP, and the circumferential direction was under a negative strain state during the entire cardiac cycle. After valve excision from the exsanguinated heart, the MVAL contracted significantly (18% and 30% in the circumferential and radial directions, respectively), indicating the presence of substantial in-vivo residual strains. While the physiological function of the residual strains (and their associated stresses) are at present unknown, accounting for their presence is clearly necessary for accurate computational simulations of MV function. Moreover, we demonstrated that changes in annular geometry dramatically alter valvular functional strains in-vivo. As levels of homeostatic strains are related to tissue remodeling and homeostasis, our results suggest that surgically-introduced alterations in MV shape could lead to the long term MV mechanobiological and microstructural alterations that could ultimately affect MV repair durability.
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影响因子：
2.9
作者：
Einstein DR;Del Pin F;Jiao X;Kuprat AP;Carson JP;Kunzelman KS;Cochran RP;Guccione JM;Ratcliffe MB
通讯作者：
Ratcliffe MB
影响因子：
39.3
作者：
Adams DH;Rosenhek R;Falk V
通讯作者：
Falk V
DOI：
10.1016/s0022-5223(96)70056-9
发表时间：
1996-09-01
影响因子：
6
作者：
Gorman, JH;Gupta, KB;Edmunds, LH
通讯作者：
Edmunds, LH
DOI：
10.1016/s0022-5223(98)00450-4
发表时间：
1998-11-01
影响因子：
6
作者：
Gillinov, AM;Cosgrove, DM;Loop, FD
通讯作者：
Loop, FD
影响因子：
3.3
作者：
FUNG, YC;LIU, SQ
通讯作者：
LIU, SQ