Anisotropic and nonlinear biaxial mechanical response of porcine small bowel mesentery. (February 2018)

• Record Type: Journal Article
• Authors: Amini Khoiy, Keyvan; Abdulhai, Sophia; Glenn, Ian C.; Ponsky, Todd A.; Amini, Rouzbeh
• Is Part Of: Journal of the mechanical behavior of biomedical materials. Volume 78(2018)
• Page Start: 154
• Page End: 163
• Publication Date: 2018-02
• Subjects: Mesentery tissue -- Mechanical properties -- Biaxial testing -- Constitutive modeling; Biomedical materials -- Periodicals; Biomedical materials -- Mechanical properties -- Periodicals; Biomedical materials; Biomedical materials -- Mechanical properties; Periodicals; Electronic journals; 610.28
• DOI: 10.1016/j.jmbbm.2017.11.017
• Languages: English
• ISSNs: 1751-6161

Abstract

Abstract: Intestinal malrotation places pediatric patients at the risk of midgut volvulus, a complication that can lead to ischemic bowel, short gut syndrome, and even death. Even though the treatments for symptomatic patients of this complication are clear, it is still a challenge to identify asymptomatic patients who are at a higher risk of midgut volvulus and decide on a suitable course of treatment. Development of an accurate computerized model of this intestinal abnormality could help in gaining a better understanding of its integral behavior. To aid in developing such a model, in the current study, we have characterized the biaxial mechanical properties of the porcine small bowel mesentery. First, the tissue stress–strain response was determined using a biaxial tensile testing equipment. The stress–strain data were then fitted into a Fung-type phenomenological constitutive model to quantify the tissue material parameters. The stress–strain responses were highly nonlinear, showing more compliance at the lower strains following by a rapid transition into a stiffer response at higher strains. The tissue was anisotropic and showed more stiffness in the radial direction. The data fitted the Fung-type constitutive model with an average R-squared value of 0.93 . An averaging scheme was used to produce a set of material parameters which can represent the generic mechanical behavior of the tissue in the models. Graphical abstract: Highlights: The stress–strain response was highly nonlinear and anisotropic. A Fung-type constitutive model predicted the stress–strain response accurately. Material properties were obtained for each specimen at distinct anatomical regions. A set of average parameters was provided for future finite element simulations.