A thorough understanding of the aortic root structure and biomechanics is necessary when performing aortic valve-sparing procedures in patients with aortic root aneurysms. This study aimed to evaluate the amount of collagen and biomechanics at different levels and segments of the aortic root. Ten aortic roots from healthy pigs were excised including the aortic annulus, the sinuses of Valsalva, and the sinotubular junction (STJ). Specimens were further divided into three circumferential segments; left sinus (LC), right sinus (RC), and non-coronary (NC) sinus. Collagen was determined using hydroxyproline analysis and specimens were tested biomechanically for stress-strain relations. The annulus showed significantly larger average maximum stiffness (9.6±4.5N/mm) compared with the sinus (4.5±2.0N/mm) and STJ (4.8±1.8N/mm). The average collagen content was likewise higher in the annulus (4.0±1.0mg/ml) compared with the sinus (2.4±0.6mg/ml) and STJ (2.2±0.5mg/ml) for all three segments. The NC sinus segment exhibited a significantly larger maximum stiffness and stress under static conditions compared with the RC. These results suggest that the aortic root is heterogeneous in both structure and biomechanical properties and that it varies both in levels and segments of the aortic root. Future surgical approaches should consider enhanced strength parameters for specific areas of the aortic root to achieve the best results when performing aortic valve-sparing techniques. From this study, we conclude that the aortic annulus needs special attention to imitate normal physiologic properties during aortic valve-sparing surgery due to its higher maximum stiffness, stress, and load. Modified future surgical procedures could potentially prevent recurrent aneurysmal formation.

对患有主动脉瘤的患者进行主动脉瓣膜保留手术时，必须对主动脉根结构和生物力学有透彻的了解。这项研究旨在评估主动脉根部不同水平和节段胶原蛋白和生物力学的数量。从健康猪中切除了十个主动脉根，包括主动脉瓣环，瓦尔萨尔瓦窦和窦管交界处（STJ）。标本被进一步分为三个圆周部分。左鼻窦（LC），右鼻窦（RC）和非冠状动脉（NC）鼻窦。使用羟脯氨酸分析确定胶原蛋白，并通过生物力学测试标本的应力-应变关系。与窦（4.5±2.0N / mm）和STJ（4.8±1.8N / mm）相比，环空的平均最大刚度（9.6±4.5N / mm）大得多。在所有三个节段中，与窦（2.4±0.6mg / ml）和STJ（2.2±0.5mg / ml）相比，瓣环中的平均胶原蛋白含量同样更高（4.0±1.0mg / ml）。与RC相比，NC窦段在静态条件下表现出明显更大的最大刚度和应力。这些结果表明，主动脉根在结构和生物力学特性上都是异质的，并且其水平和节段都不同。未来的外科手术方法应考虑在执行主动脉瓣保留技术时针对主动脉根特定区域增强强度参数，以达到最佳效果。根据这项研究，我们得出结论，主动脉瓣环在保留主动脉瓣膜的手术过程中需要特别注意模仿正常的生理特性，因为其最大的刚度，应力，和加载。修改后的手术程序可能会阻止复发性动脉瘤的形成。