Department of Surgery, Advocate Lutheran General Hospital, Park Ridge, Illinois.
National Coalition on Healthcare, Washington, District of Columbia.
J Surg Res. 2019 Sep;241:240-246. doi: 10.1016/j.jss.2019.04.003. Epub 2019 Apr 28.
Designing peripheral arterial stents has proved challenging, as implanted devices will repetitively and unpredictably deform and fatigue during movement. Preclinical testing is often inadequate, given the lack of relevant animal models. The purpose of this study was to test the hypothesis that deformation of the human peripheral vasculature could be qualitatively and quantitatively modeled using an experimental animal.
Anteroposterior contrast angiography was performed in domestic Landrace-Yorkshire farm pigs. Images were obtained with the hind limbs naturally extended then repeated, (1) flexed approximately 90° at the hip and knee, (2) overflexed in a nonphysiological fashion. Quantitative vascular angiographic analysis was utilized to measure arterial diameter, length, and deformation. Percent axial arterial compression and bending were assessed.
Eight iliofemoral arteries in four animals were imaged. Mean luminal diameters of the iliac and femoral segments in the neutral position were 5.4 ± 0.5 mm and 4.6 ± 0.5 mm. Hind limb physiologic flexion induced profound arterial compression, 17 ± 8% and 29 ± 6% and bending, 36°±10° and 76° ± 13° within the iliac and femoral segments, respectively. With extreme flexion, the femoral artery could be reliably bent >90°. The observed findings exceeded the deformation observed historically within the human superficial femoral (∼5% compression and 10° bending) and popliteal artery (∼10% compression and 70° bending).
Significant nonradial deformation of the porcine iliofemoral arteries was observed during manual hind limb flexion and exceeded that typically observed in humans. This model constitutes a "worst case" scenario for testing deformation and fatigue of intravascular devices indicated for the human peripheral vasculature.
设计外周动脉支架具有挑战性，因为植入的装置在运动过程中会反复且不可预测地变形和疲劳。由于缺乏相关的动物模型，临床前测试往往不够充分。本研究的目的是验证这样一个假设，即使用实验动物可以定性和定量地模拟人体周围脉管系统的变形。
对家猪（Landrace-Yorkshire 杂交猪）进行前后位对比血管造影。后腿自然伸展后，重复（1）髋关节和膝关节弯曲约 90°，（2）以非生理方式过度弯曲，以获取图像。利用定量血管造影分析测量动脉直径、长度和变形。评估动脉的轴向压缩和弯曲百分比。
对四只动物的 8 条股髂动脉进行了成像。中立位时髂动脉和股动脉的管腔直径分别为 5.4±0.5mm 和 4.6±0.5mm。下肢生理弯曲会导致动脉严重受压，在髂动脉和股动脉段分别为 17±8%和 29±6%；弯曲度为 36°±10°和 76°±13°。在极度弯曲时，股动脉可以可靠地弯曲超过 90°。观察到的变形超过了历史上在人体股浅动脉（约 5%的压缩和 10°的弯曲）和腘动脉（约 10%的压缩和 70°的弯曲）中观察到的变形。
在手动弯曲后肢时，观察到猪的股髂动脉会发生显著的非径向变形，超过了人体通常观察到的变形。该模型构成了测试用于人体周围脉管系统的血管内装置的变形和疲劳的“最坏情况”场景。
