Zhao Erin, Barber Jared, Sen Chandan K, Arciero Julia
Department of Mathematical Sciences, Indiana University - Purdue University Indianapolis, Indianapolis, Indiana, USA.
Indiana Center for Regenerative Medicine and Engineering, Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Microcirculation. 2021 Nov 15:e12738. doi: 10.1111/micc.12738.
To incorporate chronic vascular adaptations into a mathematical model of the rat hindlimb to simulate flow restoration following total occlusion of the femoral artery.
A vascular wall mechanics model is used to simulate acute and chronic vascular adaptations in the collateral arteries and collateral-dependent arterioles of the rat hindlimb. On an acute timeframe, the vascular tone of collateral arteries and distal arterioles is determined by responses to pressure, shear stress, and metabolic demand. On a chronic timeframe, sustained dilation of arteries and arterioles induces outward vessel remodeling represented by increased passive vessel diameter (arteriogenesis), and low venous oxygen saturation levels induce the growth of new capillaries represented by increased capillary number (angiogenesis).
The model predicts that flow compensation to an occlusion is enhanced primarily by arteriogenesis of the collateral arteries on a chronic time frame. Blood flow autoregulation is predicted to be disrupted and to occur for higher pressure values following femoral arterial occlusion.
Structural adaptation of the vasculature allows for increased blood flow to the collateral-dependent region after occlusion. Although flow is still below pre-occlusion levels, model predictions indicate that interventions which enhance collateral arteriogenesis would have the greatest potential for restoring flow.
将慢性血管适应性纳入大鼠后肢数学模型，以模拟股动脉完全闭塞后的血流恢复情况。
使用血管壁力学模型模拟大鼠后肢侧支动脉和侧支依赖小动脉的急性和慢性血管适应性。在急性时间框架内，侧支动脉和远端小动脉的血管张力由对压力、剪切应力和代谢需求的反应决定。在慢性时间框架内，动脉和小动脉的持续扩张会导致向外的血管重塑，表现为被动血管直径增加（动脉生成），而低静脉血氧饱和度水平会导致新毛细血管生长，表现为毛细血管数量增加（血管生成）。
该模型预测，在慢性时间框架内，对闭塞的血流补偿主要通过侧支动脉的动脉生成得到增强。预计股动脉闭塞后，血流自动调节会受到干扰，且在更高压力值时才会发生。
血管系统的结构适应性使得闭塞后侧支依赖区域的血流增加。尽管血流仍低于闭塞前水平，但模型预测表明，增强侧支动脉生成的干预措施在恢复血流方面具有最大潜力。
