Extracellular matrix fiber microarchitecture is region-specific in bicuspid aortic valve-associated ascending aortopathy.
Extracellular matrix fiber microarchitecture is region-specific in bicuspid aortic valve-associated ascending aortopathy.
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DOI：
10.1016/j.jtcvs.2016.02.019
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发表时间：
2016-06
期刊：
影响因子：
--
通讯作者：
Gleason TG
中科院分区：
文献类型：
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作者：
Tsamis A;Phillippi JA;Koch RG;Chan PG;Krawiec JT;D'Amore A;Watkins SC;Wagner WR;Vorp DA;Gleason TG
与三尖瓣主动脉瓣（TAV）患者相比，二叶式主动脉瓣（BAV）患者的升胸主动脉瘤（ATAA）通常不对称扩张。动脉瘤几何形状的这种差异使我们假设微结构差异是观察到的不对称扩张模式的基础。本研究的目的是表征2种表型细胞外基质的微结构差异，重点关注不同周向主动脉区域中径向弹性蛋白和胶原纤维的比例。从接受择期动脉瘤修复术的BAV或TAV患者的窦管交界处远端获得主动脉组织环。根据相邻的主动脉窦段（左冠状窦[L]、右冠状窦[R]或非冠状窦[N]），将其分为三个周向区域。多光子显微镜被用来量化和表征径向取向的弹性蛋白和胶原纤维的数量。与TAV-ATAA相比，BAV-ATAA的内侧区域N和内侧-内膜区域R中的放射状定向纤维较少内侧区N，弹性蛋白角波动幅度= 10.67° ± 1.35° vs 15.58° ± 1.91°; P = 0.041;内侧-内膜区R，弹性蛋白的角度波动幅度= 9.83° ± 0.83° vs 14.72° ± 1.64°; P = 0.015）。相反，与TAV-ATAA相比，BAV-ATAA的内侧-内膜区域L中的纤维变得更加径向定向（胶原的角度波动幅度= 18.67° ± 0.95° vs 14.56° ± 1.37°; P = 0.041）。在L和N-R区域之间注意到的纤维取向的差异模式有助于解释BAV-ATAA的大弯扩张的独特模式。基质微结构中的差异可能构成这些不同瓣膜形态中ATAA中不同动脉瘤几何形状和主动脉壁完整性的基础。
Ascending thoracic aortic aneurysm (ATAA) in patients with bicuspid aortic valve (BAV) commonly dilate asymmetrically compared with patients with tricuspid aortic valve (TAV). This discrepancy in aneurysm geometry led us to hypothesize that microarchitectural differences underlie the observed asymmetric dilatation pattern. The purpose of this study was to characterize the microarchitectural distinctions of the extracellular matrix of the 2 phenotypes with a focus on the proportion of radially oriented elastin and collagen fibers in different circumferential aortic regions. Aortic tissue rings were obtained just distal to the sinotubular junction from patients with BAV or TAV undergoing elective aneurysm repair. They were sectioned into three circumferentially based regions according to adjacent aortic sinus segment (left coronary sinus [L], right coronary sinus [R], or noncoronary sinus [N]). Multiphoton microscopy was used to quantify and characterize the number of radially oriented elastin and collagen fibers. There were fewer radially oriented fibers in medial region N and medial-intimal region R of BAV-ATAAs when compared with TAV-ATAAs (medial region N, amplitude of angular undulation of elastin = 10.67° ± 1.35° vs 15.58° ± 1.91°; P = .041; medial-intimal region R, amplitude of angular undulation of elastin = 9.83° ± 0.83° vs 14.72° ± 1.64°; P = .015). Conversely, fibers became more radially oriented in the medial-intimal region L of BAV-ATAA when compared with TAV-ATAA (amplitude of angular undulation of collagen = 18.67° ± 0.95° vs 14.56° ± 1.37°; P = .041). The differential pattern of fiber orientation noted between L and N-R regions help explain the unique pattern of greater curvature dilatation of BAV-ATAA. The distinctions noted in matrix microarchitecture may form the basis of differing aneurysm geometries and aortic wall integrities in ATAAs arising in these different valve morphologies.