Tissue Mechanics Laboratory, The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States.
Pediatric Cardiology, Connecticut Children's Medical Center, Hartford, CT, United States.
J Mech Behav Biomed Mater. 2019 Jan;89:9-12. doi: 10.1016/j.jmbbm.2018.08.053. Epub 2018 Aug 31.
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.
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.
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.
先天性心脏病（CHD）是导致儿科死亡的主要原因，许多病例影响右心室流出道（RVOT）或肺动脉瓣（PV）。了解疾病的力学特性可以深入了解耐用修复技术和生物工程替代设备的发展。本工作对两名儿科患者的肺动脉瓣进行了力学和结构分析。
作为手术程序的一部分，切除了两个 PV 组织。一个 PV 来自患有努南综合征（患者 1）的 9 个月大的婴儿，另一个来自患有三尖瓣闭锁（患者 2）的 6 个月大的婴儿。对瓣膜进行平面双轴拉伸测试和二次谐波产生（SHG）成像，以进行力学和结构评估。
患者 1 的力学响应比患者 2 表现出更强的各向异性，样本的刚度与成人 PV 组织相当。此外，两个样本在瓣膜的心室侧和纤维侧都显示出胶原纤维的径向和周向排列。纤维侧的胶原纤维也比心室侧更卷曲。
