Toward Elucidating the Physiological Impacts of Residual Stresses in the Colorectum
Toward Elucidating the Physiological Impacts of Residual Stresses in the Colorectum
复制标题
阐明结直肠残余应力的生理影响
DOI：
10.1115/1.4051846
复制
发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Pierce, D. M.
中科院分区：
文献类型：
--
作者：
Zhao, Y.;Siri, S.;Feng, B.;Pierce, D. M.
肠易激综合征折磨着全球10-20%的人口，引起内脏疼痛，对结肠直肠膨胀和正常肠道运动的敏感性增加。理解和预测这些生物力学将进一步促进我们对内脏疼痛的理解，并补充现有的内脏神经生理学文献。我们最近在小鼠远端30毫米结直肠的三个纵段（结肠、中间和直肠）进行了一系列实验。我们还建立并拟合了本构模型，以解决结直肠在厚度和纵向上的力学异质性。传入神经末梢，位于粘膜下层，可能是伤害感受器，检测机械压力的浓度，唤起内脏对疼痛的感知。在本研究中，我们的目标是：(1)建立并验证将残余应力纳入结直肠模型的方法；(2)预测残余应力对结直肠组织内力学的影响；(3)在体内建立结直肠组织内拉伸和应力的分布。为此，我们基于实验证据开发了结直肠的双层复合有限元模型，并根据独立的实验数据验证了我们的方法。我们通过有限元软件febio内置的预应变算法在模拟中包含了层和段特定的残余拉伸/应力。我们的模型和建模方法使研究人员能够预测结直肠的器官和组织内生物力学，并可能有助于更好地理解内脏疼痛的潜在力学机制。
Irritable bowel syndrome afflicts 10–20% of the global population, causing visceral pain with increased sensitivity to colorectal distension and normal bowel movements. Understanding and predicting these biomechanics will further advance our understanding of visceral pain and complement the existing literature on visceral neurophysiology. We recently performed a series of experiments at three longitudinal segments (colonic, intermediate, and rectal) of the distal 30 mm of colorectums of mice. We also established and fitted constitutive models addressing mechanical heterogeneity in both the through-thickness and longitudinal directions of the colorectum. Afferent nerve endings, strategically located within the submucosa, are likely nociceptors that detect concentrations of mechanical stresses to evoke the perception of pain from the viscera. In this study, we aim to: (1) establish and validate a method for incorporating residual stresses into models of colorectums, (2) predict the effects of residual stresses on the intratissue mechanics within the colorectum, and (3) establish intratissue distributions of stretches and stresses within the colorectum in vivo. To these ends we developed two-layered, composite finite element models of the colorectum based on our experimental evidence and validated our approaches against independent experimental data. We included layer- and segment-specific residual stretches/stresses in our simulations via the prestrain algorithm built into the finite element softwarefebio. Our models and modeling approaches allow researchers to predict both organ and intratissue biomechanics of the colorectum and may facilitate better understanding of the underlying mechanical mechanisms of visceral pain.