Bhat Sanchita S, Berland Katelynne, Ncho Beatrice E, Kawashima Takayuki, Kozaki Satoshi, Uchida Kaoru, Mori Kazuki, Gorman Robert C, Gorman Joseph H, Yoganathan Ajit P
Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia.
Gorman Cardiovascular Research Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
Ann Thorac Surg Short Rep. 2024 Dec 13;3(2):549-554. doi: 10.1016/j.atssr.2024.12.002. eCollection 2025 Jun.
Annuloplasty ring dehiscence post ischemic mitral regurgitation is an extensively studied mode of failure. This study aimed to compare annuloplasty ring designs of varying stiffness and investigate annular forces to understand mechanisms that may mitigate likelihood of ring dehiscence.
Force transducers were attached to 5 types of rings-rigid, flexible, COM-Flex, POST-Flex, and ALPM-Flex-having varying stiffness. After undersized ring implantation in diseased animals (N = 31), ring suture forces (F) were measured for peak left ventricular pressures of 100, 125, and 150 mm Hg.
In normotensive animals, anterior F was highest in POST-Flex rings (2.2 ± 0.73 N). Posterior F was considerably lower in flexible (0.7 ± 0.10 N) compared with rigid (1.6 ± 0.27 N) and COM-Flex (1.1 ± 0.13 N) rings. POST-Flex rings had notable differences between anterior F (2.2 ± 0.73 N) and posterior F (1.4 ± 0.38 N). ALPM-Flex and COM-Flex rings had anterior F of 1.6 ± 0.47 N and 1.6 ± 0.25 N, and posterior F of 1.2 ± 0.45 N and 1.1 ± 0.13 N, respectively.
Results demonstrate trends in suture forces and their spatial variation. COM-Flex was most effective in distributing forces away from posterior annulus. Despite POST-Flex having large material heterogeneity, average posterior force was similar to rigid rings. Results shown in this study provide an atlas of data on how variable annular loading is and the complexity of both understanding loads and developing devices to sustain them.
缺血性二尖瓣反流后瓣环成形环裂开是一种得到广泛研究的失败模式。本研究旨在比较不同硬度的瓣环成形环设计，并研究瓣环受力情况，以了解可能降低环裂开可能性的机制。
将力传感器连接到5种具有不同硬度的环上，即刚性环、柔性环、COM-Flex环、POST-Flex环和ALPM-Flex环。在患病动物（n = 31）中植入尺寸偏小的环后，测量左心室峰值压力为100、125和150 mmHg时的环缝合力（F）。
在血压正常的动物中，POST-Flex环的前向F最高（2.2±0.73 N）。与刚性环（1.6±0.27 N）和COM-Flex环（1.1±0.13 N）相比，柔性环的后向F（0.7±0.10 N）要低得多。POST-Flex环的前向F（2.2±0.73 N）和后向F（1.4±0.38 N）之间存在显著差异。ALPM-Flex环和COM-Flex环的前向F分别为1.6±0.47 N和1.6±0.25 N，后向F分别为1.2±0.45 N和1.1±0.13 N。
结果表明了缝合力及其空间变化的趋势。COM-Flex环在将力从后瓣环分散开方面最有效。尽管POST-Flex环具有较大的材料异质性，但其平均后向力与刚性环相似。本研究所示结果提供了一份关于瓣环负荷变化情况以及理解负荷和开发承受负荷装置的复杂性的数据图谱。
