人股动脉血管的径向拉伸性能

Radial tensile properties of human femoral artery

目的:为进一步改进人造血管的生物力学特性,需对正常人体动脉血管的生物力学特性进行表征,观察正常人股动脉内外膜间的微观特征,分析其径向方向重复疲劳拉伸和一次性断裂拉伸的相关特性。方法:试验于2007-03/10在华中科技大学同济医学院附属协和医院完成。45岁男性患者由于突发下肢股动脉栓塞,导致肢体坏死而行大腿高位截肢,术毕截取一段正常人体的股动脉(患者对试验及治疗知情同意,治疗方案经医院医学伦理委员会批准),利用光学放大镜从微观上分析人股动脉内外膜间的结构特征,万能强力仪对这段血管进行径向重复疲劳拉伸和一次性断裂拉伸试验。结果:人股动脉主要由内中外3层结构组成,内膜层的内表面呈绒状的凸凹不平,具有微孔结构,外表面则呈沟槽状的突起;中膜层由大量弹性纤维所组成;外膜层非常致密光滑。股动脉径向应力随着疲劳拉伸次数的增加而减小,经100次拉伸后,应力从0.80N减小到0.40N,减小率大约50.00%;但衰减主要发生在拉伸初期,到60次以后衰减率明显下降。经过反复疲劳拉伸的血管与初始血管原样在拉伸断裂性能上基本相似。结论:拉伸测试发现人体动脉血管的拉伸初始模量较低,随着变形的增大,模量和弹性恢复能力会逐渐减弱,但最后趋于稳定平衡,显示其具有较好的抗疲劳拉伸性能。

AIM: In order to improve the biomechanical characteristics of the man-made blood vessel, we made a biomechanical research about the normal human arterial vessel and the morphology of the normal human femoral arterial intima and adventitia, and analyze the correlation between the radial repeated fatigable elongation and disposable broken elongation. METHODS: The test was made in Union Hospital, Tongji Medical College of Huazhong University of Science & Technology, from March to October in 2007. One 45-year old man suffering from sudden femoral arterial embolism and necrosis of the lower limb, was adopted in this study. Informed consent was obtained from this male patient, and the treatment was approved by the hospital ethical committee. After high amputation, the removed femoral artery was cut into segments. The structures of femoral arterial intima and adventitia were observed on an optical magnifying lens. Universal strength tester was used to conduct radial repeated fatigable elongation test and disposable broken elongation test. RESULTS: Human femoral artery was consisted of 3 layers: intima, midlayer and adventitia. The inside surface of intima was velvet, uneven and microporous while the outside surface of intima was furrow-like prominence; the midlayer comprised a large amount of elastic fibers; the surface of adventitia was smooth and compact. The radial stress force of femoral artery decreased with the increasing tensile times, after 100 cycles of elongation, the force declined from 0.80 N to 0.40 N, accounting for 50.00%; The decrease mainly occurred during the initial cycles, and then attenuated slowly after 60 cycles. The vessels undergoing repeated fatigable elongation were identical with the controlled vessels regarding tensile property. CONCLUSION: Tensile tests reveal that, the initial modulus of human arterial vessels is relatively low. With the deformation heightens, the modulus and elasticity recovery taper and finally stabilize, showing good anti-fatigable elongation properties.