Departments of Cardiothoracic Surgery, Weill Cornell Medicine, New York, New York, United States of America.
Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy.
PLoS One. 2020 Mar 12;15(3):e0230208. doi: 10.1371/journal.pone.0230208. eCollection 2020.
In patients with ascending aortic (AA) aneurysms, prosthetic graft replacement yields benefit but risk for complications in the descending aorta persists. Longitudinal impact of AA grafts on native descending aortic physiology is poorly understood.
Transthoracic echocardiograms (echo) in patients undergoing AA elective surgical grafting were analyzed: Descending aortic deformation indices included global circumferential strain (GCS), time to peak (TTP) strain, and fractional area change (FAC). Computed tomography (CT) was used to assess aortic wall thickness and calcification.
46 patients undergoing AA grafting were studied; 65% had congenital or genetically-associated AA (30% bicuspid valve, 22% Marfan, 13% other): After grafting (6.4±7.5 months), native descending aortic distension increased, irrespective of whether assessed based on circumferential strain or area-based methods (both p<0.001). Increased distensibility paralleled altered kinetics, as evidenced by decreased time to peak strain (p = 0.01) and increased velocity (p = 0.002). Augmented distensibility and flow velocity occurred despite similar pre- and post-graft blood pressure and medications (all p = NS), and was independent of pre-surgical aortic regurgitation or change in left ventricular stroke volume (both p = NS). Magnitude of change in GCS and FAC was 5-10 fold greater among patients with congenital or genetically associated AA vs. degenerative AA (p<0.001), paralleling larger descending aortic size, greater wall thickness, and higher prevalence of calcific atherosclerotic plaque in the degenerative group (all p<0.05). In multivariate analysis, congenital/genetically associated AA etiology conferred a 4-fold increment in magnitude of augmented native descending aortic strain after proximal grafting (B = 4.19 [CI 1.6, 6.8]; p = 0.002) independent of age and descending aortic size.
Prosthetic graft replacement of the ascending aorta increases magnitude and rapidity of distal aortic distension. Graft effects are greatest with congenital or genetically associated AA, providing a potential mechanism for increased energy transmission to the native descending aorta and adverse post-surgical aortic remodeling.
在升主动脉（AA）动脉瘤患者中，人工移植物置换可带来获益，但降主动脉的并发症风险仍然存在。AA 移植物对降主动脉自然生理的纵向影响知之甚少。
分析接受 AA 择期手术移植物置换的患者的经胸超声心动图（echo）：降主动脉变形指数包括整体周向应变（GCS）、峰值应变时间（TTP）应变和面积分数变化（FAC）。使用计算机断层扫描（CT）评估主动脉壁厚度和钙化。
研究了 46 名接受 AA 移植物置换的患者；65%为先天性或遗传性 AA（30%二叶式主动脉瓣，22%马凡氏综合征，13%其他）：移植物置换后（6.4±7.5 个月），无论基于周向应变还是基于面积的方法评估，降主动脉自然扩张均增加（均 p<0.001）。顺应性增加与动力学改变平行，表现为峰值应变时间缩短（p = 0.01）和速度增加（p = 0.002）。尽管术前和术后血压和药物使用情况相似（均 p = NS），但顺应性和血流速度增加，并且与术前主动脉瓣反流或左心室射血分数变化无关（均 p = NS）。与退行性 AA 相比，先天性或遗传性 AA 患者的 GCS 和 FAC 变化幅度大 5-10 倍（p<0.001），与退行性 AA 组相比，降主动脉较大、壁较厚、钙化性动脉粥样硬化斑块发生率较高（均 p<0.05）。多元分析显示，先天性/遗传性 AA 病因使近端移植物置换后降主动脉自然应变增强的幅度增加 4 倍（B = 4.19 [CI 1.6, 6.8]；p = 0.002），与年龄和降主动脉大小无关。
升主动脉人工移植物置换增加了远端主动脉扩张的幅度和速度。移植物的影响在先天性或遗传性 AA 中最大，这为能量传递到降主动脉并导致术后主动脉重塑不良提供了一个潜在机制。
