Mechanical characterization of the human femoral vein wall and its valves

IF 3.3 2区医学 Q2 ENGINEERING, BIOMEDICAL

Journal of the Mechanical Behavior of Biomedical Materials Pub Date : 2025-02-10 DOI:10.1016/j.jmbbm.2025.106938

Kerstin Lebahn , Jonas Keiler , Wolfram Schmidt , Julia Schubert , Maria Reumann , Andreas Wree , Niels Grabow , Sabine Kischkel

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引用次数: 0

Abstract

For the development of stent-based intraluminal prostheses to treat chronic venous insufficiency, comprehensive knowledge of morphometric and mechanical parameters of the femoral veins (FV) is crucial for an optimized implant design. These data is essential as input for material models for numerical simulations of venous valves prostheses. However, data on mechanical properties of native/unfixed FV tissue are scarce. Unfixed native tissue, though, has limited availableness and durability due to progressing decay. To address these challenges, this study aimed to determine stress-strain behavior and compliance from native specimens of the human FV and its valves from body donations and compared the data to chemically fixed material.

A large data set has been generated in tensile tests with a total of 313 venous wall and 78 valve leaflet specimens in different fixation groups from a total of 41 body donations. Tensile testing was conducted at cut rectangular specimens in longitudinal as well as circumferential direction of the vein walls and in one specific direction for the valve leaflets. Young's moduli E₁ and E₂ in two differently defined strain regions, tensile strength R_m and elongation at break A were determined. Additionally, compliance measurements were performed at whole, unfixed vein segments using optical coherence tomography to determine the vessel diameter at increasing intravascular pressure from 20 to 240 mmHg.

Significant differences were found in the tensile parameters between unfixed tissue and the different fixations (exemplary Young's modulus E₁ in longitudinal direction: E_{1, unfixed} = 5.7 ± 5.1 N/mm², E_{1, FA} = 13.1 ± 11.9 N/mm², E_{1, PFA} = 2.3 ± 1.0 N/mm). A distinct anisotropy of the mechanical properties could only be detected for PFA fixed material when comparing longitudinal and circumferential tensile direction. Resultant mean compliance values over all segments and measuring positions of the vein segments for the analyzed pressure stages were in the range from 18.16 to 3.78 %/100 mmHg and showed a distinct decrease with increasing pressure.

Fixation (FA, PFA) alters the elastomechanical behavior, but the parameters were still in a similar order of magnitude considering the naturally occurring variability. Thus, testing of fixed tissue appears to be as appropriate as the use of this material for ex vivo testing. The provided material data of femoral veins (longitudinal and circumferential) as well as venous valve leaflets may serve as basis for numerical models, e.g. for the development of artificial venous valves.

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人股静脉壁及其瓣膜的力学特性

为了开发基于支架的腔内假体来治疗慢性静脉功能不全，全面了解股静脉（FV）的形态测量学和力学参数对于优化植入物设计至关重要。这些数据对于静脉瓣膜假体数值模拟的材料模型的输入是必不可少的。然而，关于原生/非固定FV组织力学性能的数据很少。然而，未固定的天然组织由于不断腐烂，其可用性和耐久性有限。为了解决这些挑战，本研究旨在确定来自人体捐赠的人类FV及其瓣膜的本地标本的应力-应变行为和顺应性，并将数据与化学固定材料进行比较。在拉伸试验中产生了一个庞大的数据集，其中包括来自41个捐赠体的不同固定组的313个静脉壁和78个瓣膜小叶标本。在剪开的矩形试件上沿静脉壁的纵向和周向以及阀叶的一个特定方向进行拉伸试验。测定了两个不同定义应变区的杨氏模量E1和E2、抗拉强度Rm和断裂伸长率A。此外，使用光学相干断层扫描对整个非固定静脉段进行依从性测量，以确定血管内压力从20增加到240 mmHg时的血管直径。不同固定方式下未固定组织的拉伸参数差异有统计学意义（纵向杨氏模量E1: E1，未固定= 5.7±5.1 N/mm2, E1, FA = 13.1±11.9 N/mm2, E1, PFA = 2.3±1.0 N/mm）。当比较纵向和周向拉伸方向时，PFA固定材料的力学性能具有明显的各向异性。在分析的压力阶段中，所有节段和静脉节段测量位置的平均顺应性值在18.16至3.78% /100 mmHg之间，并随着压力的增加而明显下降。固定（FA， PFA）改变了弹性力学行为，但考虑到自然发生的变异性，参数仍然处于相似的数量级。因此，固定组织的测试似乎与使用这种材料进行离体测试一样合适。所提供的股静脉（纵向和周向）以及静脉瓣小叶的材料数据可以作为数值模型的基础，例如用于人工静脉瓣的开发。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of the Mechanical Behavior of Biomedical Materials 工程技术-材料科学：生物材料

CiteScore

7.20

自引率

7.70%

发文量

505

审稿时长

46 days

期刊介绍： The Journal of the Mechanical Behavior of Biomedical Materials is concerned with the mechanical deformation, damage and failure under applied forces, of biological material (at the tissue, cellular and molecular levels) and of biomaterials, i.e. those materials which are designed to mimic or replace biological materials. The primary focus of the journal is the synthesis of materials science, biology, and medical and dental science. Reports of fundamental scientific investigations are welcome, as are articles concerned with the practical application of materials in medical devices. Both experimental and theoretical work is of interest; theoretical papers will normally include comparison of predictions with experimental data, though we recognize that this may not always be appropriate. The journal also publishes technical notes concerned with emerging experimental or theoretical techniques, letters to the editor and, by invitation, review articles and papers describing existing techniques for the benefit of an interdisciplinary readership.