Objective

Congenital Heart Disease (CHD) is the leading cause of pediatric mortality, with many cases affecting the right ventricular outflow tract (RVOT) or pulmonary valve (PV). Understanding the mechanics of the disease condition can provide insight into development of durable repair techniques and bioengineered replacement devices. This work presents a mechanical and structural analysis of the pulmonary valve of two pediatric cases.

Methods

Two PV tissues were excised as part of the operative procedure. One PV was obtained from a 9-month-old with Noonan syndrome (Patient 1) and the other from a 6-month-old with tricuspid atresia (Patient 2). The leaflets were subjected to planar biaxial tensile testing and second harmonic generation (SHG) imaging for mechanical and structural evaluation.

Results and discussion

Patient 1 exhibited a more anisotropic mechanical response than Patient 2, with sample stiffness on par with that of adult PV tissue. Additionally, both samples showed radial and circumferential alignment of collagen fibers on the ventricularis and fibrosa sides of the leaflets, respectively. Collagen fibers on the fibrosa side were also more crimped than on the ventricularis side.

中文翻译：

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先天性心脏缺损的肺动脉瓣的机械和结构分析：两个案例研究的介绍。

客观的

先天性心脏病（CHD）是小儿死亡率的主要原因，许多病例影响右心室流出道（RVOT）或肺动脉瓣（PV）。了解疾病状况的机理可以提供对持久修复技术和生物工程替代设备开发的见识。这项工作提出了两个儿科病例的肺动脉瓣的机械和结构分析。

方法

作为手术过程的一部分，切除了两个PV组织。一种是从9个月大的Noonan综合征（患者1）获得的，另一种是从6个月大的三尖瓣闭锁症（患者2）获得的。对小叶进行平面双轴拉伸测试和二次谐波生成（SHG）成像，以进行机械和结构评估。

结果与讨论

患者1表现出比患者2更高的各向异性机械响应，其样品刚度与成人PV组织的刚度相当。另外，两个样品均分别显示小叶的心室侧和纤维侧上的胶原纤维的径向和周向对齐。与心室侧相比，纤维侧的胶原纤维也更卷曲。