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Design of Abdominal Wall Hernioplasty Meshes Guided by Mechanobiology and the Wound Healing Response
Published in Jiro Nagatomi, Eno Essien Ebong, Mechanobiology Handbook, 2018
Shawn J. Peniston, Karen J.L. Burg, Shalaby W. Shalaby
The rectus sheath is divided by the posterior and anterior layer relative to the rectus abdominis muscle and is comprised of the aponeurosis from each layer of the triple flat abdominal muscles. The anterior layer of the rectus sheath is made up of primarily aponeurosis fiber from the external and internal oblique muscles and the posterior layer is comprised of aponeurosis fibers from the internal oblique and transversus muscles above the level of arcuate line. The arcuate line is generally located midway between the umbilicus and pubis and represents the transition zone in which the aponeurosis of the external oblique, the internal oblique, and the transversus abdominis muscles all pass anterior to the rectus muscle [39]. Below the arcuate line the posterior sheath of the rectus abdominis lacks strength as it is comprised of only transversalis fascia, areolar tissue, and peritoneum [39]. It should be noted that aponeurosis are like tendons or ligaments, with the major difference being that they originate from large flat muscles and thus take on the form of large, flat, thin sheets. Fascial layers on the other hand are considerably more extensible and primarily function to separate layers of tissue rather than provide load bearing structural support. For this reason the myopectineal orifice is susceptible to herniation.
Mg-RE-Based Alloy Systems for Biomedical Applications
Published in Yufeng Zheng, Magnesium Alloys as Degradable Biomaterials, 2015
The Mg-2Y-1Zn alloy showed promising mechanical performance and microstructural stability in a previous study of Hanzi et al. (2010). In order to gain insight into the in vivo performance of the Mg-2Y-1Zn alloy, a preliminary animal study on Gottingen minipigs was performed. Sample disks of 4 mm diameter and 0.4 mm thickness were implanted into four different types of tissue in the abdomen (liver, lesser omentum) and in the abdominal wall (rectus abdominis muscle, subcutaneous tissue), respectively. All animals were in good general condition until sacrifice and showed no adverse reactions. Figure 11.18 shows the histopathological preparations derived from Mg-2Y-1Zn samples in various types of tissues, and it indicates homogeneous degradation and only limited gas formation during in vivo testing. The characteristics of the tissue reactions indicate good biocompatibility, and the Mg-2Y-1Zn alloy is believed to be promising for degradable implant applications.
Global sensitivity analysis of membrane model of abdominal wall with surgical mesh
Published in Wojciech Pietraszkiewicz, Wojciech Witkowski, Shell Structures: Theory and Applications Volume 4, 2017
K. Szepietowska, I. Lubowiecka, B. Magnain, E. Florentin
The following results presented by Song et al. (2006) imply the material model assumed orthotropic. The material parameters are the same, but orientation is different. The abdominal wall model has been divided into 2 areas: central part corresponding to area of rectus abdominis muscle and linea alba with rectus sheath. In this area material direction corresponding to E1 is assumed to be in transverse direction. Lateral part corresponds to composite of lateral muscles and their fascias. Elasticity E1, E2 and G12, pressurep and orientation of lateral part αaw are assumed to be uniformly distributed random variables (Table 1).
Characterization of subcutaneous pelvic adipose tissue morphology and composition at the plane of the ASIS: A retrospective study of living subjects
Published in Traffic Injury Prevention, 2022
Austin M. Moore, Samantha M. Efobi, Jazmine Aira, Ashley A. Weaver, Leon Lenchik, Fang-Chi Hsu, F. Scott Gayzik
An axis of symmetry was drawn through the linea alba anteriorly and midline of sacrum posteriorly. Next, a vector was drawn from the anterior aspect of the sacroiliac (SI) joint to the ipsilateral ASIS bilaterally. This vector was used to then establish three measures of SAT depth at the ASIS: along line from SI, lateral (traditionally thought of as the “Y” axis, patient left – right), and anterior-posterior (traditionally thought of as the “X” axis). Tissue depth at ASIS was measured from the cortical surface to the exterior surface of the skin. SAT thickness was also measured at three other locations, normal to the external surface of the skin: bilaterally at the lateral border of rectus abdominis muscle, and along midline at linea alba. An example of the depth measures can be seen in Figure 1. Three experienced image analysts performed the analysis independently on the same image data to test for inter-observer bias and protocol repeatability. In some cases, the protocol required the assumption of left-right symmetry because the full cross section of the patient was not in view. However, no images were missing the right or left ASIS.
The effects of the muscular contraction on the abdominal biomechanics: a numerical investigation
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2019
Piero G. Pavan, Silvia Todros, Paola Pachera, Silvia Pianigiani, Arturo N. Natali
The FE model is developed starting from a previous one in passive condition (Pachera et al. 2015). The principal abdominal components are included: linea alba, rectus abdominis muscle, aponeurosis and a structure comprising all the lateral muscles, namely IO, TA and EO (Figure 1). The abdominal wall region is modeled by means of the segmentation software ITK-SNAP (Yushkevich et al. 2006), starting from CT images of a healthy male subject and histo-morphometric data from the literature (Lancerotto et al. 2011; Rankin et al. 2006; Ambardar et al. 2009; Tahan et al. 2016). Muscles are modeled with a thickness varying in the different regions of the abdomen according to subject-specific CT images. Rough surfaces of muscular structures are subsequently smoothed and ultimate thickness is adapted to anatomical data (Rankin et al. 2006; Ambardar et al. 2009; Tahan et al. 2016). Differently, fascial structures, which cannot be precisely identified in CT images, are reconstructed on the surfaces of linea alba, aponeuroses and muscles, considering a constant thickness, according to specific data for each fascia (Lancerotto et al. 2011; Costa-Ferreira et al. 2014). The model is obtained by using ABAQUS CAE software (SIMULIA, Dassault Systems) and consists of 629,946 elements. The structures of linea alba and muscles are discretized with tetrahedral linear elements with hybrid formulation to avoid numerical instabilities due to the almost-incompressible behavior of muscular and connective tissues. The fascial structures are modeled with three node membrane elements. Frictionless contact surfaces are considered between fasciae, muscles and linea alba. The muscular fibers spatial distribution in the different muscles is shown in Figure 1.